Since it was founded in 1958, the EU has regularly accepted new member countries. Each applicant country must meet certain requirements before membership is permitted.
Regular enlargements have seen the EU grow from its original 6 founding members to 28 in 2013.
Any country that satisfies the conditions for enlargement can apply to be a candidate. The European Commission, at the request of the European Council, assesses the applicant’s ability to meet the conditions of membership. If the opinion is positive and the Council agrees a negotiating mandate, discussions are formally opened between the applicant and the EU.
At the start of 2013, five countries had been accepted as EU candidate countries: Iceland, Montenegro, the former Yugoslav Republic of Macedonia, Serbia and Turkey. Albania, Bosnia and Herzegovina and Kosovo (under UN Security Resolution 1244) have the status of potential candidates.