Montenegro submitted an application for EU membership on 15th December 2008. In line with Article 49 of the EU Treaty, the Member States requested, on 23 April 2009, that the European Commission prepare an opinion upon the merits of the application.
On 22 July 2009 European Commissioner for Enlargement Olli Rehn handed over to Montenegro’s authorities a Questionnaire to help prepare an assessment of the country's readiness to fulfil EU membership obligations. On 9 December, Montenegro’s Prime Minister Milo Djukanovic delivered the answers to the EC's questionnaire to Commissioner Rehn.
The European Commission has acknowledged that Montenegro has made significant progress toward opening talks on EU membership and voiced support and gave recommendation for its candidate status on 9 November 2010 and on 17 December 2010 the European Union granted Montenegro the official status of candidate country.
The accession negotiations with Montenegro were opened on 29 June 2012. As of 13 December 2016, 26 negotiating Chapters, including the rule of law Chapters, 23 – Judiciary and fundamental rights and 24 – Justice, freedom and security, have been opened, out which two Chapters (25 – Science and research and 26 – Education and culture) have been provisionally closed. Opening benchmarks have been set for 11 Chapters.
Diplomatic relations between Montenegro and the European Union are conducted through the Mission of Montenegro to the EU in Brussels, which has been fully functional since 2006, and the EU Delegation to Montenegro in Podgorica, which opened in November 2007.