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
League of Nations mandate June 1919. With the dissolution of the League of Nations after World War II, it was stipulated at the Yalta Conference that the remaining Mandates should be placed under the trusteeship of the United Nations, subject to future discussions and formal agreements. Most of the remaining mandates of the League of Nations (with the exception of South-West Africa) thus eventually became United Nations Trust Territories. Two governing principles formed the core of the Mandate System, being non-annexation of the territory and its administration as a “sacred trust of civilisation” to develop the territory for the benefit of its native people.