Colombia, US announce joint exercises with nuclear sub

Earlier this month, Colombia accused Russia of "foreign interference" on its border with Venezuela where two left-wing guerrilla groups have been fighting deadly battles for control of lucrative drug-trafficking routes.

Russia dismissed the claims from Bogota, which also accuses Venezuela of harboring armed rebels on its soil.

Colombia's defense minister Diego Molano said the exercises would strengthen the fight against drug-trafficking and protect "national sovereignty."

"For the first time, a US nuclear submarine participated in interoperability exercises in the Colombian Caribbean Sea," said Molano in a video statement released on Monday.

The exercises began on Sunday but Molano gave no indication of how long they would last nor how many US troops were involved.

Venezuela reacted with fury to the news.

"Is it a replica of NATO expansion in the American Mediterranean?" said Defense Minister General Vladimir Padrino on Twitter.

"Drug trafficking, the war in (the Colombian region of) Arauca, systematic murders and terrorist groups cannot be fought with nuclear submarines."

On February 3, Molano claimed Venezuelan military units had been "mobilized to the border with the support and technical strength of Russia."

Moscow denied the allegations.

In May last year, in the midst of unprecedented anti-government protests, Colombia accused Russia of involvement in cyber attacks against official websites.

Moscow also rejected those claims.

In December, Russian Deputy Foreign Minister Sergei Ryabkov threatened to send forces to allies Venezuela or Cuba if it did not get its way with NATO over Ukraine.

Colombia is the only strategic NATO partner in Latin America and is also a close US ally.

Moscow had been demanding a guarantee from NATO - the military alliance between mostly Western countries -- that Ukraine never be allowed to join.

NATO refused and last week Russia invaded its western neighbor.