Venezuelan President Hugo Chavez has announced trade measures against Colombia, amid a growing diplomatic row between the two nations.
“These bases could be the start of a war in South America – we’re talking about the Yankees, the most aggressive nation in human history.”
Mr Chavez said he would halt the import of 10,000 cars from Colombia and ban a Colombian energy firm from Venezuela’s oil-rich region.
Last week, Mr Chavez recalled his envoy from Bogota over accusations that Venezuela had sold arms to Farc rebels.
He is also angry over Bogota’s plans to boost US military presence in Colombia.
Colombian President Alvaro Uribe is currently visiting Chile and Argentina – on the latest stage of his regional tour to try to reassure South American leaders over the deployment of US troops.
A number of South American nations – including Chile, Argentina, Brazil and Bolivia – have expressed concerns over Bogota’s plans.
Washington wants to increase its military capabilities in Colombia to counter drug traffickers and left-wing rebels, say analysts.
Speaking at a news conference in Caracas, Mr Chavez said the Venezuelan government would halt the import of 10,000 mainly industrial cars from the neighbouring Colombia.
He also said Colombia’s Ecopetrol company would be barred from taking part in an auction to develop the heavy crude in Venezuela’s oil-rich Orinoco region.
Mr Chavez went on to say Venezuela would seek to buy “several battalions of Russian tanks” during his visit to Russia in September, reports AP news agency.
“These bases could be the start of a war in South America,” the socialist leader told reporters. “We’re talking about the Yankees, the most aggressive nation in human history.”
Mr Chavez also rebuffed Bogota’s accusations that Caracas had been selling weapons to the left-wing Farc rebel group.
Alvaro Uribe is seen by many as Washington’s main ally in the region
He said that rocket launchers and automatic rifles found in a Colombian rebel camp had been stolen from a Venezuelan naval post 14 years ago.
The Venezuelan leader identified a wide range of products that Venezuela imported from Colombia, including meat, dairy and cereals, saying he would be looking for other nations to do business with.
“We’re going to replace all of these imports.
“It’s our responsibility because at any stage Yankees could say ‘send no more meat to Chavez’ or ‘don’t send the Venezuelans’, because it is the Yankees who are going to rule over there – not Uribe,” Mr Chavez said.
Colombia is a vital provider of food, plastic goods and automobiles to Venezuela, in exchange for gas from the Opec member, says the BBC’s Will Grant in Caracas.
Bilateral trade between Venezuela and Colombia amounts to about $7bn (£4bn) a year, and some analysts suggest it will not be easy for Mr Chavez to replace it, he adds.
But our correspondent says that Mr Chavez remains adamant that it can be done, saying that Venezuela’s “trade with Colombia isn’t indispensible”.
A close Chavez ally, Bolivian President Evo Morales, said on Wednesday that Washington was using Colombia’s Farc rebels as an excuse for military operations in the region.
“We can’t have all these planes and military equipment concentrated in Colombia… This isn’t against drug-trafficking, it’s against the region. Our duty is to reject it,” said Mr Morales, a day after his meeting with Mr Uribe.