Bulgaria joined the UN on 14 December 1955 and participates in the ECE and all the non-regional specialized agencies. It belongs to the WTO, and is a signatory of the Law of the Sea, and has applied for EU membership. Since the early 1970s, the Bulgarian government has tried to improve relations with other Balkan states. In 1971, a consular agreement was reached with Turkey. Bulgaria signed consular and cultural agreements with Greece in 1973, and a declaration of friendship and cooperation in 1986. A Bulgaro-Yugoslav Economic Chamber was set up in 1982 to promote mutual trade. In November 2002, Bulgaria was invited to join NATO, and is to be admitted in 2004.