Union of South American Nations in Mitad del Mundo, Ecuador, where the cornerstone was laid for the headquarters of the General Secretariat of the Union. In April 2018, six countries suspended membership: Argentina, Brazil, Chile, Colombia, Paraguay and Peru. In August 2018, Colombia announced its withdrawal from the organization. At the Third South American Summit on 8 December 2004, presidents or representatives from 12 South American nations signed the "Cusco Declaration", a two-page statement of intent announcing the foundation of the South American Community. Panama and Mexico attended the signing ceremony as observers in Brazil. The mechanics of the new entity came out of the
Union of South American Nations that the union would have on the world stage. The name was finally changed on 16 April 2007 to "Union of South American Nations". The new name was jointly agreed by all member states during the first day of meeting at the First South American Energy Summit, held at Isla Margarita, Venezuela. After Colombian Ernesto Samper completed his term as Secretary General in January 2017, the UNASUR governments have been unable to reach consensus on the organization's future leadership. Venezuela, with the support of Bolivia and Suriname, has blocked the nomination of Argentine diplomat José Octavio Bordón. In August 2017,