President Hugo Chavez has threatened to halt oil sales to the United States if Venezuela is attacked by its US-allied neighbour Colombia.
Chavez said during a speech to thousands of supporters that if there were an "armed aggression against Venezuela" from Colombia backed by the US, "we would suspend shipments of oil".
Chavez said "we wouldn't send one more drop" of oil to the United States, which is the top buyer of oil from the South American country.
The Venezuelan leader cut off diplomatic relations with Colombia on Thursday after outgoing President Alvaro Uribe's government presented photos, videos and maps of what it said were Colombian rebel camps inside Venezuela.
Chavez calls it a bogus show intended to smear his government and has said the Uribe could be trying to lay the groundwork for an armed conflict.
The Colombian government denies seeking a conflict. It says it went to the Organisation of American States with its evidence about the rebels' alleged presence in Venezuela last week because Chavez's government had not taken steps to address the situation.
Chavez said Sunday he is cancelling a trip to Cuba due to the tensions with Colombia.
He said separately in a newspaper column, however, he will wait to see if Colombian President-elect Juan Manuel Santos, who takes office next month, expresses willingness to ease the diplomatic conflict.
"We have to receive clear and unequivocal signals that there is a real political will in the new Colombian government to take up the path of dialogue again, without tricks," Chavez wrote.© 2010 AP