CARACAS, Venezuela - President Hugo Chavez on Friday accused Colombia and the United States of plotting a military "aggression" against Venezuela. "A military aggression is being prepared from Colombia against Venezuela by the United States," Chavez said. He warned Colombia not to attempt "a provocation against Venezuela" and said his country would cut off all oil exports in the event of a military strike from the neighboring country. Chavez did not offer evidence to support his claim. He has repeatedly accused the United States of plotting to oust him or kill him, though it was the first time he has accused Colombia's U.S.-allied government in such strident terms. "I accuse the government of Colombia of devising a conspiracy, acting as a pawn of the U.S. empire, of devising a military provocation against Venezuela," Chavez said. He made the accusation just as Secretary of State Condoleezza Rice was visiting Colombia, saying she and two other senior American officials who have visited in Bogota recently "came to attack Venezuela" in their remarks. Rice did not mention Chavez during her earlier statements in Colombia. Colombian presidential spokesman Cesar Mauricio Velasquez said his government had no immediate comment.