Potential enlargement of the European Union

Six candidates are currently engaged in active negotiations: Montenegro (since 2012), Serbia (since 2014), Albania (since 2022), North Macedonia (since 2022), Moldova and Ukraine (since 2024). The most advanced stage of the negotiations, defined as meeting the interim benchmarks for negotiating chapters 23 and 24, after which the closing process for all chapters can begin, has so far been reached by Montenegro (in 2024) and by Albania (in 2026). Montenegro's declared political goal is to complete its negotiations by the end of 2026 and achieve membership of the EU by 2028, whereas Albania aims to conclude negotiations by 2028 at the latest, potentially joining the EU shortly after Montenegro.

The accession criteria are included in the Copenhagen criteria, agreed in 1993, and the Treaty of Maastricht (Article 49). Article 49 of the Maastricht Treaty (as amended) says that any "European state" that respects the "principles of liberty, democracy, respect for human rights and fundamental freedoms, and the rule of law," may apply to join the EU. Whether a country is European or not is subject to political assessment by the EU institutions. Past enlargement since the foundation of the European Union as the European Economic Community by the Inner Six states in 1958 brought total membership of the EU to twenty-eight, although, as a result of the withdrawal of the United Kingdom, the current number of EU member states is twenty-seven.

Of the four major Western European countries that are not EU members, Norway, Switzerland, and Iceland have submitted membership applications in the past but subsequently froze or withdrew them, while the United Kingdom is a former member, as the only country to ever leave the EU. Norway, Switzerland, and Iceland, as well as Liechtenstein, participate in the EU Single Market and also in the Schengen Area, which makes them closely aligned with the EU; none, however, are in the EU Customs Union.

Current agenda and applicants

As of 2026, the enlargement agenda of the European Union regards three distinct groups of states:

• Western Balkans: Albania, Bosnia and Herzegovina, Kosovo, Montenegro, North Macedonia, and Serbia
• Association Trio: Georgia, Moldova, and Ukraine
• Turkey

These states have all submitted applications for accession to the EU, which is the first step of a long, multi-year process. They must subsequently negotiate the specific terms of their Treaty of Accession with the current EU member states, and align their domestic legislation with the accepted body of EU law (acquis communautaire), along with ensuring an appropriate level of implementation thereof, before joining.

There are other potential member states in Europe that are not formally part of the current enlargement agenda, either due to having a domestic political debate on potential membership, or having withdrawn a previous membership or application for membership. These other potential member states could be included on the enlargement agenda at some point of time in the future, if their foreign policy changes and paves the way for submitting an application, and the EU subsequently recognises them as an applicant or candidate.

Historically, the norm was for enlargements to consist of multiple entrants simultaneously joining the European Economic Community (1958–1993) and the EU (since 1993). The only previous enlargements of a single state were the 1981 admission of Greece and the 2013 admission of Croatia. However, following the significant effect of the fifth enlargement in 2004, EU member states have decided that a more individualised approach will be adopted in the future, although the entry of pairs or small groups of countries may coincide.

Procedure to become an EU member state

For an applicant to become a member state of the EU, several procedural steps need to get passed. These steps will move the status of the state from applicant (potential candidate) to candidate, and later move on to the status of a negotiating candidate. The status as a negotiating candidate is reached by the mutual signing of a negotiation framework at the first intergovernmental conference. The start of substantial negotiations with the EU is subsequently marked by the opening of the first negotiating chapters at a second intergovernmental conference. All 35 chapters of the accepted body of EU law (divided into 6 clusters) must be opened and closed during subsequent additional intergovernmental conferences for a state to conclude the negotiations by the signing of an accession treaty.

Following a reform in 2020, the 35 chapters have been divided into six main clusters, where all five chapters of the first cluster are supposed to be opened together at the same time. The opening of chapters, which after the reform occur with several chapters opened together cluster-wise, can only happen by a unanimous decision by the Council of the European Union once the screening procedure report has been completed for the specific chapters (outlining all needed legislative changes to comply with EU law), while there can also be set some "opening benchmarks" requiring a certain amount of legislative changes/implementation to be met even before the opening of the chapters. The closure of a chapter is done provisionally by a unanimous decision by the Council of the European Union once the state demonstrates that it has implemented and aligned its domestic legislation with the EU law, for each specific chapter in concern.

There are no requirements for completion of the screening procedure for all 35 negotiating chapters, before the start of the first and second intergovernmental conferences.

Due to the Primacy of European Union law over the constitution of member states with few exceptions a potential enlargement can require a referendum related to the accession to the European Union or a constitutional amendment.

Western Balkans

The 2003 European Council summit in Thessaloniki set the integration of the Western Balkans as a priority of EU expansion.

Slovenia was the first former Yugoslav country to join the EU in 2004, followed by Croatia in 2013.

Albania, Bosnia and Herzegovina, Montenegro, North Macedonia, and Serbia have all been officially granted candidate status. Kosovo, which is claimed by Serbia and not recognised by 5 EU states, applied on 14 December 2022 and is considered a potential candidate by the European Union.

Serbia, Albania, and Montenegro, as the most advanced candidates in their negotiation processes with the EU, may join the EU sometime between 2028 and 2030, considering the 18 to 24-month ratification process, which starts after the negotiations are completed. Montenegro's declared political goal is to complete its negotiations by the end of 2026 and achieve membership of the EU by 2028.

The European Council had endorsed starting negotiations with Albania and North Macedonia on 26 March 2020, however, the negotiation process was blocked by Bulgaria for over two years. In June 2022, French President Emmanuel Macron submitted a compromise proposal which, if adopted by both countries, would pave the way for the immediate adoption of negotiating frameworks for North Macedonia and Albania by the EU Council and for the organisation of intergovernmental conferences with them. On 24 June 2022, Bulgaria's parliament approved the revised French proposal to lift the country's veto on opening EU accession talks with North Macedonia, with the Assembly of North Macedonia also doing so on 16 July 2022, allowing accession negotiations to begin. On the same day, the start of negotiations was set for 19 July 2022.

On 8 November 2023, the European Commission adopted a new Growth Plan for the Western Balkans, with the aim of bringing them closer to the EU through offering some of the benefits of EU membership to the region in advance of accession. The Growth Plan provides €6 billion in financial grants and loans for the entire region in return for the implementation of structural reforms. Besides the core financial support of the growth plan, one of the additional embedded priority actions is granting access to the Single Euro Payments Area.

On 8 November 2023, the European Commission recommended opening negotiations with Bosnia and Herzegovina once the necessary degree of compliance with the membership criteria is achieved. On 12 March 2024, the European Commission recommended opening EU membership negotiations with Bosnia and Herzegovina, citing the positive results from important reforms the country enacted. On 21 March 2024, all 27 EU leaders, representing the European Council, gathered for a summit in Brussels, where they unanimously granted conditional approval for opening EU membership negotiations with Bosnia and Herzegovina. On 17 December 2024, the Council reiterated that they still needed to receive an approved Growth Plan reform package along with a national programme for the adoption of EU law, and that the country should appoint a chief negotiator and a national IPA III coordinator, before the adoption of a negotiation framework can happen as the next step of the process for Bosnia and Herzegovina.

On 25 December 2024, the National Assembly of Republika Srpska (a federal entity of Bosnia and Herzegovina) adopted conclusions alleging the erosion of the legal order in Bosnia and Herzegovina, and demanded the "annulment of all acts resulting from unconstitutional actions by foreign individuals (High Representatives) who lack the constitutional authority to propose or enact laws", and "requires representatives from Republika Srpska in state institutions to suspend decisions related to European integration (as well as all decision-making concerned to the overall level of the country) until the process aligns with democratic principles and the rule of law". However, the High Representative issued an order on 2 January 2025 that prohibited the implementation with immediate legal effect of the entirety of these conclusions, due to having found them to violate Republika Srpska's obligations and commitments under the Dayton Agreement. On 8 January 2025, the President of Republika Srpska, Milorad Dodik, stated that he would seriously reconsider whether Republika Srpska should pursue the European path, as he instead preferred efforts to secede the entity from Bosnia and Herzegovina, and rejected the authority of the Constitutional Court and High Representative. The Delegation of the European Union to Bosnia and Herzegovina stated in response: "The sovereignty, territorial integrity, constitutional order – including Constitutional Court decisions – and international personality of Bosnia and Herzegovina need to be respected. The EU urges the political leadership of the Republika Srpska to refrain from and renounce provocative, divisive rhetoric and actions, including questioning the sovereignty, unity and territorial integrity of the country. The EU urges all political actors in BiH to take resolute action to implement the necessary reforms to advance on the EU path towards opening EU accession negotiations. We reiterate our full commitment to the EU accession perspective of BiH as a single, united and sovereign country".

Association Trio

In 2005, the European Commission suggested in a strategy paper that the present enlargement agenda could potentially block the possibility of a future accession of Armenia, Azerbaijan, Belarus, Georgia, Moldova, and Ukraine. Olli Rehn, the European Commissioner for Enlargement between 2004 and 2010, said on the occasion that the EU should "avoid overstretching our capacity, and instead consolidate our enlargement agenda," adding, "this is already a challenging agenda for our accession process." In May 2009, the Eastern Partnership was established as a specific dimension of the European Neighbourhood Policy, which contains both a bilateral and multilateral track for six Eastern neighbours to the European Union (Armenia, Azerbaijan, Belarus, Georgia, Moldova, and Ukraine), in the form of an institutionalised forum for discussing visa agreements, free trade deals, and strategic partnership agreements, while there is no requirement to pursue accession to the European Union.

The European Parliament passed a resolution in April 2014 stating that "in accordance with Article 49 of the Treaty on European Union, Georgia, Moldova and Ukraine, as well as any other European country, have a European perspective and can apply for EU membership in compliance with the principles of democracy, respect for fundamental freedoms and human rights, minority rights and ensuring the rule of rights." In 2016-17 Association Agreements between the EU and Georgia, Moldova, and Ukraine were ratified, and collectively these three countries became referred to as the Association Trio. They also entered the Deep and Comprehensive Free Trade Area with the EU, which creates "framework for modernising [...] trade relations and for economic development by the opening of markets via the progressive removal of customs tariffs and quotas, and by an extensive harmonisation of laws, norms and regulations in various trade-related sectors, creating the conditions for aligning key sectors" of their economies with EU standards. However, the EU did not expand further into the post-Soviet space in the 2010s.

As of December 2019, the Association Trio is sometimes expanded to the Trio + 1 with the inclusion of Armenia, which is not formally on the EU's enlargement agenda but is considering submitting an application for membership.

By January 2021, Georgia and Ukraine were preparing to formally apply for EU membership in 2024. However, following the 2022 Russian invasion of Ukraine, Ukraine submitted an application for EU membership on 28 February 2022, followed by Georgia and Moldova on 3 March 2022. On 23 June 2022, the European Council granted candidate status to Moldova and Ukraine, and recognised Georgia as a potential candidate for membership. When taking its candidacy decision for Ukraine and Moldova, the Council made opening the accession negotiations conditional to addressing respectively seven and nine key areas related to strengthening the rule of law, fighting corruption and improving governance processes.

In his speech in Moldova on 28 March 2023, President of the European Council Charles Michel mentioned that "by the end of the year, the Council will have to decide on the opening negotiations with [Ukraine and Moldova]. It will be a political decision taking into account the report that will be published by the Commission. And I sincerely hope that a positive decision will be possible by the end of the year".

On 8 November 2023, the European Commission recommended opening negotiations with Moldova and Ukraine, and granting candidate status to Georgia, and this was agreed by the European Council on 14 December 2023.

On 25 June 2024, the first Intergovernmental Conference (IGC) was called by the Belgian Presidency of the Council of the EU, officially marking the start of the accession negotiations with Moldova and Ukraine.

On 9 July 2024, following the adoption of a law by Georgia's ruling Georgian Dream party requiring non-governmental and media entities to register as "foreign agents", the EU ambassador in Georgia announced that in response the EU would de facto halt the country's accession progress, with no further steps to advance the process to be expected and no financial support granted for as long as the law exists. The European Union has threatened Georgia with sanctions and suspension of relations if the country becomes a "one-party state" without political opposition following parliamentary elections in October 2024.

The 2024 Georgian parliamentary elections resulted in Georgian Dream retaining power, but were disputed by opposition parties which claimed that the vote was not free and fair and was subject to widespread voter fraud. The European Parliament adopted a non-binding resolution which rejected the validity of the results, and called for the vote to be repeated within a year. Following this, Georgian Prime Minister Irakli Kobakhidze stated that accession negotiations would be suspended until the end of 2028, though he insisted that his government would continue to implement the reforms required for accession and that it still planned for Georgia to join the EU by 2030.

The EU have halted all financial aid for the Georgian government since 27 June 2024, and instead redirected its financial support only to be received by civil society and the media in Georgia. Similar to the growth plans and IPA III grants launched towards supporting structural reforms to improve accession perspectives for candidates from the Western Balkans, the EU launched – or is about to launch – similar growth plan programmes for Ukraine and Moldova:

• Ukraine Facility: Established on 29 February 2024. Provides up to €50 billion over four years to support financial stability, recovery, and implementation of key reforms to assist in the Accession of Ukraine to the European Union between 2024 and 2027.
• Reform and Growth Facility for Moldova: Establishment pending ongoing legal approval in 2025. Provides up to €285 million in grants and €1.5 billion in loans with long repayment time and advantageous interest rates, during the period from 2025 to 2027. The facility is the financial pillar of the Moldova Growth Plan, but will also assist in the Accession of Moldova to the European Union and in undertaking EU-related reforms. Payments will be subject to strict conditions in terms of the achievement of reforms set out in the agreed Reform Agenda.

In October 2024, the Moldovan EU membership constitutional referendum resulted in support to amend the Constitution of Moldova to include the aim of becoming an EU member state.

Turkey

Turkey's candidacy to join the EU has been a matter of major significance and considerable controversy since it was granted in 1999. Turkey has had historically close ties with the EU, having an association agreement since 1964, being in a customs union with the EU since 1995 and initially applying to join in 1987. Only after a summit in Brussels on 17 December 2004 (following the major 2004 enlargement) did the European Council announce that membership negotiations with Turkey were officially opened on 3 October 2005.

Turkey is the eleventh largest economy in the world (measured as Purchasing Power Parity), and is a key regional power. In 2006, Carl Bildt, former Swedish foreign minister, stated that "[The accession of Turkey] would give the EU a decisive role for stability in the Eastern part of the Mediterranean and the Black Sea, which is clearly in the strategic interest of Europe." However, others, such as former French President Nicolas Sarkozy and former German Chancellor Angela Merkel, expressed opposition to Turkey's membership. Opponents argue that Turkey does not respect the key principles that are expected in a liberal democracy, such as the freedom of expression.

Turkey's large population would also alter the balance of power in the representative European institutions. Upon joining the EU, Turkey's 84 million inhabitants would bestow it the largest number of MEPs in the European Parliament. It would become the most populous country in the EU. Another problem is that Turkey does not recognise one EU member state, Cyprus, because of the Cyprus problem, and the Cypriot government blocks some chapters of Turkey's talks.

EU–Turkey relations have deteriorated following President Erdoğan's crackdown on supporters of the 2016 Turkish coup d'état attempt. While Erdoğan stated that he approved the reintroduction of the death penalty to punish those involved in the coup, the EU announced that it strongly condemned the coup attempt and would officially end accession negotiations with Turkey if the death penalty was reintroduced. On 25 July 2016, President of the European Commission Jean-Claude Juncker said that Turkey was not in a position to become a member of the European Union in the near future and that accession negotiations between the EU and Turkey would be stopped immediately if the death penalty was brought back. On 24 November 2016, the European Parliament approved a non-binding resolution calling for the "temporary freeze of the ongoing accession negotiations with Turkey" over human rights and rule of law concerns. On 13 December 2016, the European Council (comprising the heads of state or government of the member states) resolved that it would open no new areas in Turkey's membership talks in the "prevailing circumstances", as Turkey's path toward autocratic rule made progress on EU accession impossible. On 6 July 2017, the European Parliament accepted the call for the suspension of full membership negotiations between the EU and Turkey, and a repeat of the exact same vote ended with the same result in March 2019 and May 2021. On 17 July 2018, then-Austrian Chancellor Sebastian Kurz said that it would be beneficial to end the accession negotiations between the EU and Turkey and instead develop bilateral relations between the EU and Turkey. As of 2022, and especially following Erdoğan's victory in the constitutional referendum, Turkish accession talks are effectively at a standstill.

In July 2023, Erdoğan brought up Turkey's accession to EU membership in the context of Sweden's application for NATO membership. However, in September 2023, he announced that the European Union was well into a rupture in its relations with Turkey and that they could part ways during Turkey's European Union membership process. Former CHP and current New Party leader and Turkey's main opposition leader Özgür Özel announced that if he wins the next Turkish general elections, his country will rapidly continue its accession negotiations with the EU and his country will become a member of the EU as soon as possible.

Summary table

Timeline

Level of preparation for acquis chapters

2025 situation

The table below shows the level of preparation of applicant countries with EU standards (acquis communautaire) on a 5-point scale, using data from the European Commission's 2025 reports. The analysis is based on the analysis performed by the online media outlet European Pravda.

Progress from 2024 to 2025

The table below shows the progress over the past year of applicant countries on a 4-point scale, using data from the European Commission's 2025 reports. The analysis is based on the analysis performed by the online media outlet European Pravda.