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. Formation The complete integration between the Andean Community and the Mercosur nations was formalized during the meeting of South American heads of state that took place on 23 May 2008 in Brasília. In the 2004 South American Summit, representatives of twelve South American nations signed the Cuzco Declaration, a two-page letter of intent announcing the establishment of the then-named "South American Community of Nations". Panama and Mexico were present as observers. The leaders announced the intention of modeling the new community in the mold of the European Union, including a unified passport, a parliament and, eventually, a single currency. The then Secretary General of the Andean Community Allan Wagner speculated that an advanced union such as the EU should be possible within the next fifteen years. After Argentina, Bolivia, Chile, Ecuador, Guyana, Peru, Suriname and Venezuela, Uruguay became the ninth nation to ratify the constitutive treaty of the organization on 1 December 2010, thus completing the minimum number of ratifications Necessary for the entry into force of the Treaty, on 11 March 2011 With the entry into force of the Treaty, UNASUR became a legal entity during the Summit Ministers of Foreign Affairs, in Mitad del Mundo, Ecuador, where the cornerstone was laid for the headquarters of the General Secretariat of the Union. Naming On 28 December 2005, Chilean former foreign minister Ignacio Walker proposed that the Union's former designation, the South American Community of Nations, abbreviated as CSN, be changed to South American Union; nevertheless, many members responded that that proposal had already been rejected to prevent confusion since its acronym of U.S.A. (Spanish: Unión Sudamericana) would be easily confused for the United States of America. In the press, the phrase "United States of South America" was bandied about as an analogy to the United States to reflect the economic and political power 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