Addressing journalists in Caracas, Maduro said he had ordered the country's armed forces "to respond forcefully to (Colombian President) Ivan Duque's reckless statements about Venezuela."

He also told them to "clean the barrels of our rifles to answer them at any level we need to answer if Ivan Duque dares violate the sovereignty of Venezuela."

On Monday last week, Duque announced an elite unit -- dubbed the Specialist Commando against Drug-trafficking and Transnational Threats -- would be "fully operational" in May.

He said the "aim for this year is to strike at the heads of narcoterrorism" and claimed "many of them are protected in Venezuela".

Duque did not mention direct military action on Venezuelan territory.

"If Ivan Duque dares to touch a millimeter of Venezuelan territory... Don't be crazy Ivan Duque! Know your limits and respect Venezuela," said Maduro, whose presidency is not recognized by Colombia.

Bogota and a string of other countries recognise opposition leader Juan Guaido as interim president, prompting Venezuela to break diplomatic ties with its neighbor. The countries regularly trade insults.

Maduro claimed the accusations from Colombia were meant to divert attention from its own "serious problems".

In 2008, Colombia executed a FARC leader on Ecuadorian soil, sparking a serious diplomatic crisis with Quito, whose president at the time, Rafael Correa, was a socialist ally of Venezuela's.

Despite the 2016 peace accord, Colombia continues to battle a multi-faceted armed conflict involving leftist guerrillas, drug-traffickers and right-wing paramilitaries competing for control of the lucrative cocaine and illegal mineral extraction industries.

Colombia has repeatedly accused Venezuela of providing refuge to armed groups, which Caracas denies.