Venezuela has started to block Colombian imports and investment amounting to billions of dollars under orders from President Hugo Chavez.
The punitive move -- a response to a Colombian military attack on rebels hiding in Ecuador -- threatens economic havoc in both nations.
The dispute has become one of South America's most serious diplomatic crises in recent years.
Chavez and Ecuadorean President Rafael Correa demanded international condemnation of Colombia's U.S.-allied government on Wednesday night, while Chavez predicted a sharp fall in the $6 billion in annual Colombia-Venezuela trade: "That's coming down."
"We aren't interested in Colombian investments here," Chavez said, standing beside Correa. "Of the Colombian businesses that are here in Venezuela, we could nationalize some." Chavez is an ally of the leftist Correa.
He said Venezuela will search for other countries like Ecuador, Brazil and Argentina to replace products imported from Colombia. Noting that Colombia traditional supplies food to Venezuela, he said now "we can't depend not even for a grain of rice."
Government critics say the move will probably worsen shortages of basic foods from milk to chicken that were an annoyance in Venezuela well before the dispute began.
Chavez and Correa warned on Wednesday that the crisis would not end without clear international condemnation of Colombia's government for Saturday's deadly cross-border strike against leftist rebels.
The Organization of American States on Wednesday passed a mild resolution calling the raid on the Revolutionary Armed Forces of Colombia camp a violation of Ecuador's sovereignty.
But Correa said that while welcome, the resolution was not enough and his government still wants explicit condemnation.
"The OAS resolution pleases us. We are pleased, but not satisfied," Correa said as he visited Chavez in Caracas. "This isn't going to cool down until the aggressor is condemned."
Chavez called the attack by Colombia's U.S.-allied government a "war crime." The bombing and raid killed a top rebel leader, Raul Reyes, and 23 other guerrilla fighters who had set up a base just over a mile from the border inside Ecuador.
Colombia has accused both Chavez and Correa of close ties with the rebels. Officials said their proof were documents found on a laptop seized at the rebel base. They claimed Reyes' captured laptop was full of documents that indicate FARC political ties to both Chavez and Correa.
"This is the first time that we've stumbled across something coming from the FARC drawing such a straight line" between the rebels and Chavez, said Assistant Secretary of State Thomas A. Shannon, who said American experts would soon examine the computer's hard drive. "
Colombian President Alvaro Uribe said he would not mobilize troops or allow his nation to be drawn into war with his neighbors.
Meanwhile, Venezuela said most of the 9,000 soldiers mobilized by Chavez had reached the Colombian border area Wednesday. Ecuador said it sent 3,200 soldiers to its border with Colombia on Monday.
Chavez blamed the crisis on the U.S. "empire and its lackeys" - Colombia's conservative government - saying they pose a constant threat of war in the region.
The Venezuelan leader laughed as he dismissed accusations that the laptop's documents show he gave $300 million to the FARC and conspired with the rebels to embarrass Colombia's government.
Other documents released by Colombia show Reyes was secretly negotiating with representatives of France and other European nations to win freedom for hostages including French-Colombian politician Ingrid Betancourt and three American defense contractors.
"Any disruption in the significant trade between Colombia and Ecuador/Venezuela will be temporary," predicted David Scott Palmer, director of Latin American studies at Boston University. For Colombia, he said, "there is political fallout in bilateral relations with Ecuador, and a renewal of tension with Venezuela, but I would expect both to be temporary."
Source: The Associated Press