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 Gran Colombia and the United Provinces of Central America fell apart and the whole of Hispanic America was balkanized by competing national governments. By the 1990s, however, Brazil had consolidated as the most powerful country in South America (accounting for half of the regional GDP) and began to promote the notion of a united South America (a new regional framing) where Brasilia would be pivotal. The project did not take hold until the United States' foreign policy priorities turned to other regions in the 2000s. The complete integration between the Andean Community and the Mercosur nations was formalized during the