"We know what happened with Ecuador," he said, referring to Colombia's March 2008 cross-border strike on a base of a leftist insurgent group, the Revolutionary Armed Forces of Colombia (FARC).

Venezuela, which shares a 1,375-mile border with Colombia, severed ties with its neighbor over the weekend after outgoing President Alvaro Uribe and other Colombian officials accused Venezuela of harboring FARC forces.

"These bandits enter, do us harm, and then return to a foreign country, violating the sovereignty of brother nations," Mr. Uribe said in a speech Saturday.

His comments came two days after Colombian diplomats made a multimedia presentation before the Organization of American States, where they presented maps, photographs, videos and GPS coordinates that they said warranted an OAS investigation into FARC's presence in Venezuela.

The ambassador dismissed the OAS presentation as a "poorly acted ... media show," claiming that Venezuela had debunked similar allegations in recent years.

"We are not going to participate in the internal wars of Colombia," he said.

During the two-hour session, Mr. Alvarez also implicated the United States, saying "we don't see anything coming from Colombia without the U.S. knowing and promoting it, because if you see the script of the accusation, it's exactly the same script that has been presented by the U.S. since 2003 - and it comes sometimes from the national intelligence agencies, sometimes from the State Department, sometimes from the [Drug Enforcement Administration]."

"We also have to remember that sectors hostile to Venezuela in U.S. agencies have always fed these false accusations about the supposed support of the Venezuelan government for the Colombian insurgent groups," he added.

"This media campaign against Venezuela has served to justify a U.S. military buildup in the region. Do not forget that the U.S. government has been the main promoter of a military solution in Colombia, despite evidence of this being impossible."

The ambassador said his country is taking a wait-and-see approach regarding Colombia and might restore relations after Aug. 7, when President-elect Juan Manuel Santos - Mr. Uribe's former defense minister - takes office.

Mr. Alvarez returned to his post last year after being expelled during the waning months of the Bush administration in a tit-for-tat with Venezuelan President Hugo Chavez. The Obama administration's nominee for ambassador to Venezuela, Larry Palmer, is scheduled to testify Tuesday afternoon before the Senate Foreign Relations Committee.