Venezuela entered the South American trade bloc Mercosur in a six-nation summit this week.
In a signing ceremony, President Hugo Chavez and the leaders of Brazil, Argentina, Uruguay and Paraguay formalized the bloc's expansion to include Venezuela. Chavez called the expansion a victory against Washington's "imperialistic" economic plans for the hemisphere.
Bolivian President Evo Morales, a close Chavez ally, attended the signing ceremony as an observer.
Brazilian President Inacio Lula da Silva said anti-Americanism was not a hallmark of the regional trade bloc.