The State Union of Serbia and Montenegro applied to NATO 's Partnership for Peace ( PfP ) program in June 2003 . Montenegro declared independence on 3 June 2006 and soon after opened a Permanent Mission to NATO in Brussels . The new country subsequently joined PfP at the 2006 Riga summit . In November 2007 , Montenegro signed a transit agreement with NATO , allowing the alliance 's troops to move across the country . Montenegro then signed an agreement with the United States , in which Montenegro would destroy its outdated weaponry as a precondition for NATO membership . In late 2007 , Montenegro 's Defense Minister Boro Vučinić said that Montenegro would intensify its accession to the alliance after the 2008 Bucharest summit . Montenegro entered Intensified Dialogue with NATO in April 2008 , and adopted an Individual Partnership Action Plan in June 2008 . It was invited to join the Adriatic Charter of NATO aspirants on 25 September 2008 . The country then applied for a Membership Action Plan on 5 November 2008 with support of Prime Minister Milo Đukanović , which was granted in December 2009 . Montenegro also began full membership with the Adriatic Charter of NATO aspirants in May 2009
2008 Bucharest summit
2008 Bucharest summit
Montenegro–NATO relations