Portugal joined the UN on 14 December 1955 and participates in ECE and all the nonregional specialized agencies. The nation is one of the 12 original signatories to NATO, a member of the WTO and the Law of the Sea, and a member of OECD. It also has permanent observer status at OAS. Portugal began negotiating for entry into the EU in 1978; entry was granted officially in 1985. Portugal entered into the European economic and monetary union in 1999, and the euro entered into circulation in 2002.