The enlargement of the European Union from a Community of initially 6 Member States to a Union with 28 members, representing about 500 million citizens, can be seen as a significant step on the way to bring peace, stability and prosperity to Europe.
Seven rounds of enlargement of the original Community of six Member States have taken place so far:
Currently, the Union is negotiating or working towards starting accession negotiations with the following countries: Albania, the former Yugoslav Republic of Macedonia, Montenegro, Serbia and Turkey. Bosnia and Herzegovina, as well as Kosovo* currently have the status of being a "potential candidate country". This means, the European Council confirmed to them the prospect of EU accession in the medium to long term.
Iceland applied for EU Membership in 2009 and gained candidate status in 2010. However, in March 2015 Iceland's government requested that "Iceland should not be regarded as a candidate country for EU membership".
Turkey was recognised as a candidate country at the December 1999 Helsinki European Council. The EU launched accession negotiations with Turkey at the General Affairs Council in Luxembourg on 3 October 2005.
The former Yugoslav Republic of Macedonia received the status of candidate country by the European Council in December 2005. In October 2009, the Commission further recommended launching negotiations with the country. This has, however, not yet been agreed by the Council.
Montenegro applied in 2008 and was granted candidate country status at the December 2010 European Council. Negotiations will however be launched only upon satisfactory compliance with a set of policy conditions.
Albania applied for EU Membership in 2009 and was granted candidate country status at the June 2014 European Council.
Serbia applied in 2009 and was granted candidate country status at the May 2012 European Council.
Accession negotiations are conducted according to a negotiating framework that sets out the method and the guiding principles of the negotiations, in line with the December 2004 European Council conclusions.
The substantive negotiations are conducted in an Intergovernmental Conference with the participation of all Member States on the one hand and the candidate country on the other.
In order to ensure progress in the negotiations, the candidate countries will also need to make progress on the ground in meeting the requirements for membership, most importantly the Copenhagen criteria described below.
In order to become a Member State, candidate countries have to accept the Union's acquis communautaire - which is the body of EU laws and regulations in force in the Union. As in all previous accession negotiations, specific arrangements may be agreed. The analytical examination, commonly called 'screening', forms the first phase of accession negotiations. This process, which takes several months, enables candidate countries to familiarise themselves with the acquis, and the Commission and the Member States to evaluate the degree of preparedness of candidate countries prior to negotiations. Screening and the subsequent negotiations are organised by chapters, each covering a specific policy area.
The Commission is responsible for regularly assessing the degree of preparedness of candidate countries for accession. It delivers its assessment in progress reports published annually, normally in the autumn. Within the Commission, the Directorate-General for Economic and Financial Affairs is the department in charge of:
* "This designation is without prejudice to positions on status, and is in line with UNSCR 1244 and the ICJ Opinion on the Kosovo Declaration of Independence."