CARACAS, Aug. 30 (Xinhua) -- Colombia has found itself isolated at Friday's South American summit due to its intention to allow more U.S. military presence in the South American country, Hugo Chavez of Venezuela said here Sunday.

    The extraordinary summit of South American Union of Nations (Unasur) is called to discuss the decision made by Colombian President Alvaro Uribe to allow the installation of seven U.S. military bases on the Colombian territory.

    The move has come under strong criticism as many countries warned of U.S. military expansion in the region.

    "We don't want yankee bases in South America," the out-spoken Chavez told foreign media at Miraflores Palace, the president's official residence in Caracas.

    The 12-nation meeting showed that South America had backed self-determination in an unprecedented way and rejected U. S. hegemony, Chavez said.

    On Sunday, Chavez slammed Uribe for failing to understand the concerns of regional leaders who asked him for a copy of the final U.S.-Colombia military agreement.

    Chavez also said that trade relations with Colombia have remained frozen since a July 28 decision to freeze fuel exports and trade agreements worth around 7 billion dollars with the country.

    Chavez had threatened to cut ties with Colombia if the agreement was signed.

    "Every day the chill gets stronger. I have told the foreign minister, Nicolas Maduro, to prepare for a full break. Since then we have been ready but we are taking care to bring forward action to prevent what I believe would be a disaster on a historical scale, a war with Colombia," he said.

    He warned that three major resources in Latin America are coveted, which are Venezuela's oil, the forest riches of the Amazon and Uruguay's aquifers.