Venezuela's vice president has rebuffed U.S. criticism of his nation's plan to purchase thousands of assault rifles from Russia. He says the weapons are for defense.

Vice President Jose Vicente Rangel's statement comes after Wednesday's comment by U.S. Secretary of Defense Ronald Rumsfeld, who said in Brazil that he does not understand why Venezuela needed to purchase 100,000 AK-47s. Mr. Rumsfeld said they could pose a threat in the region.

The vice president responded by saying the U.S. defense secretary's criticisms violate Venezuela's sovereignty and are part of what he called a "systematic" U.S. campaign against President Hugo Chavez's government.

Mr. Rumsfeld is in Guatemala, the last leg of a Latin America tour. He is scheduled to meet President Oscar Berger about military reforms.