CARACAS, July 23 (Xinhua) -- Venezuelan President Hugo Chavez said Thursday that the installation of U.S. military bases in Colombia, Venezuela's neighbor, is "an unfriendly act."

    Chavez said Foreign Minister Nicolas Maduro on Wednesday met with Maria Luisa Chiappe, Colombia's ambassadress to Caracas, to inform her of the Venezuelan posture.

    The president expressed concern about the increasing presence of U.S. military bases in the region, which he said "obliges us to review the full scheme of our ties with Colombia."

    U.S. military bases in Colombia could be used to carry out attacks on Venezuela, thus bringing danger to the peace in South America, he said.

    Chavez added that in view of this, Venezuela's delegation would not attend a high-level meeting with Colombia scheduled for this week.

    Colombian officials have said the country is planning four new U.S. military bases near its border with Venezuela .