Any country seeking membership of the European Union (EU) must conform to the conditions set out by Article 49 and the principles laid down in Article 6(1) of the Treaty on European Union. Relevant criteria were established by the Copenhagen European Council in 1993 and strengthened by the Madrid European Council in 1995.

To join the EU, a new Member State must meet three criteria:

• political: stability of institutions guaranteeing democracy, the rule of law, human rights and respect for and protection of minorities;
• economic: existence of a functioning market economy and the capacity to cope with competitive pressure and market forces within the Union;
• acceptance of the Community acquis: ability to take on the obligations of membership, including adherence to the aims of political, economic and monetary union.

Any country that wishes to join the Union must meet the accession criteria. The pre-accession strategy and accession negotiations provide the necessary framework and instruments.