Since president Nicolas Maduro's capture in January, Venezuela has been "advancing in operations in the border area" and dissenting groups no longer feel safe, Sanchez said.

For decades, Colombia and Venezuela have sparred over Caracas's alleged support for leftist rebel groups that control territory and drug trafficking routes on both sides of the border.

Sanchez' comments signal what would be a major shift in security strategy under Venezuela's US-friendly interim president Delcy Rodriguez.

Sanchez said Colombia was already "coordinating" diplomatically with Caracas and that the political tumult in Caracas was "a unique opportunity" to restore security cooperation with Venezuela.

The two countries share a porous 2,200?kilometre (1,367-mile) border where various armed groups fight over revenue from drug trafficking, illegal mining and smuggling.

Operations by the new Venezuelan authorities were forcing fighters "toward the Colombian side, or in an area a little closer to the border", giving Colombia more room to strike them, Sanchez said.

This shift, he added, "has allowed us to act, as we just did", referring to an operation last week in which soldiers killed an estimated 15 ELN guerrillas.

The ELN -- the Spanish acronym for National Liberation Army -- is Colombia's biggest surviving guerrilla group, vying along the border with other armed groups who rejected a 2016 peace deal.

Under Maduro and his predecessor Hugo Chavez, ELN leaders lived in Venezuela and Colombia alleged that the presence of armed leftist fighters was tolerated.

A US indictment accuses Maduro of conspiring with rebel groups to traffic cocaine. He has pleaded not guilty.

- Friend to the north -

The shift from Venezuela comes as the United States and Colombia vowed to hunt the leaders of three armed cocaine trafficking groups.

Colombian President Gustavo Petro and US President Donald Trump recently met in Washington, trying to patch up a spat over the strategy in curbing record cocaine production.

They agreed to step up cooperation against illegal groups and drug trafficking along the border.

The new cooperation would be "mainly in intelligence", Sanchez said, adding that Colombia would not allow US troops to deploy on its soil.

The two countries were also exploring US support for an anti-drone shield to protect Colombian troops and bolster other capacities such as armoured vehicles and intelligence technology.

The goal, he said, is "how we better coordinate intelligence between the United States and Colombia in order to use Colombian force under Colombian norms and international humanitarian law against these criminal groups that commit crimes in Colombia".

Intelligence is key, he added, "so there are no grey areas" in the border region with Venezuela.

Colombia produces about 70 percent of the world's cocaine, of which the United States is the largest consumer.

Colombia has enjoyed a decade or more of relative calm since a peace agreement saw the FARC guerrilla army disarm in 2017.

But there has been a surge in violence ahead of 2026 presidential elections in May, with bomb and drone attacks in parts of the country and the assassination of a presidential hopeful.