The Organisation of American States has said Colombia violated international law last weekend.
The body stopped short of condemning Colombia for crossing into Ecuador to kill leftist militants.
It agreed in a resolution to form a commission to visit Ecuador and Colombia to investigate the Colombian raid against the FARC guerrillas that has led to a regional crisis.
Ecuador’s President, Rafael Correa, had demanded that the OAS take a firm stand against Colombia.
Venezuela said earlier it had deployed tanks and air and sea forces to the Colombian border in its first major military mobilisation of the crisis with its neighbour.
The action escalated tension in the region, which Venezuelan President Hugo Chavez said could spark a war.
While leftist allies Ecuador and Venezuela have poured soldiers toward their borders with US-backed Colombia in recent days, there had been no noticeable movement of heavy firepower.
In Washington, the Pentagon played down the troop movements, saying it saw no numbers that would be cause for concern.
On Sunday, President Chavez ordered 10 battalions (around 6,000 men) to the border with Colombia, and today General Jesus Gregorio Gonzalez said the forces were 85-90% in place.
OPEC backs Venezuela over nationalisation
In a related but separate development, OPEC today voiced support for Venezuela over its legal battle with US energy giant ExxonMobil.
Venezuela is facing a confrontation with the world's biggest oil company over its nationalisation of key oil fields in the Orinoco basin, which included two ExxonMobil operations.
ExxonMobil has won court orders in New York, London, the Netherlands and the Netherlands Antilles freezing some $12bn of assets in those jurisdictions in compensation for the expropriations.
Venezuela's state petroleum company, Petroleos de Venezuela, recently suspended oil supplies to ExxonMobil. That prompted a New York federal judge to approve a freeze of $300m in Venezuelan assets.
