Estonia was a member of the League of Nations from 22 September 1921, and became a member of the United Nations on 17 September 1991. Since restoration of independence Estonia has pursued close relations with the Western countries, and has been member of NATO since 29 March 2004, as well as the European Union since 1 May 2004. In 2007, Estonia joined the Schengen Area, and in 2011 the Eurozone. The European Union Agency for large-scale IT systems is based in Tallinn, which started operations at the end of 2012. Estonia held the Presidency of the Council of the European Union in the second half of 2017.