This document is an excerpt from the EUR-Lex website
The Treaty on European Union sets out the conditions (Article 49) and principles (Article 6(1)) to which any country wishing to become an EU member must conform.
Certain criteria must be met for admission. These criteria (known as the Copenhagen criteria) were established by the Copenhagen European Council in 1993 and strengthened by the Madrid European Council in 1995.
For EU accession negotiations to be launched, a country must satisfy the first criterion.