US President Donald Trump has confirmed he has authorised the CIA to conduct covert operations inside Venezuela, adding he is weighing carrying out land operations on the country.

The acknowledgement comes after the US military carried out a series of deadly strikes in recent weeks against alleged drug smuggling boats in the Caribbean.

US forces have destroyed at least five boats since early September, killing 27 people, with four of those vessels originating from Venezuela.

US strike on alleged drug boat off Venezuela kills six, Trump says

It is the latest such operation in recent weeks as the US builds up military forces in the region.

Asked during an event in the Oval Office on Wednesday, local time, why he had authorised the CIA to take action in Venezuela, Mr Trump confirmed he had made the move.

“I authorised for two reasons, really. Number one, they have emptied their prisons into the United States of America,” he said.

“And the other thing, the drugs, we have a lot of drugs coming in from Venezuela, and a lot of the Venezuelan drugs come in through the sea.”

Mr Trump added the administration “is looking at land” as it considers further strikes in the region.

He declined to say whether the CIA has authority to take action against President Nicolás Maduro.

A moustached middle-aged South American man thanks a crowd as he wears a red, yellow and blue starred jacket

Venezuelan President Nicolás Maduro has lashed out at the CIA. (Reuters: Fausto Torrealba)

Venezuela slams CIA operation

The US president made the unusual acknowledgement of a CIA operation shortly after The New York Times published that the CIA had been authorised to carry out covert action in Venezuela.

On Wednesday, Mr Maduro lashed out at the record of the US spy agency in various conflicts around the world without directly addressing Mr Trump’s comments about authorising the CIA to carry out covert operations in his country.

“How long will the CIA continue to carry on with its coups?” he said.

“Latin America doesn’t want them, doesn’t need them and repudiates them.”

In a statement, Venezuela’s foreign ministry on Wednesday rejected “bellicose and extravagant statements” by Mr Trump publicly admitting to authorising “operations to act against the peace and stability of Venezuela”.

“This unprecedented statement constitutes a very serious violation of international law and the United Nations’ Charter and obliges the community of countries to denounce these clearly immoderate and inconceivable statements,” the statement said.

Calls for greater clarity

Earlier this month the Trump administration declared drug cartels to be unlawful combatants, declaring the US is now in an “armed conflict” with them.

It justified the escalation as a necessary step to stem the flow of drugs into the US.

Could the US force Venezuelan regime change?

The US signals it will continue a military campaign in Latin America against “narco-terrorist organisations,” as experts warn the next step could be to remove Venezuela’s president from power.

The move has spurred anger in Congress from members of both major political parties that Trump is effectively committing an act of war without seeking congressional authorisation.

On Wednesday, Democrat Senator Jeanne Shaheen said while she supports cracking down on trafficking, the administration has gone too far.

“The Trump administration’s authorisation of covert CIA action, conducting lethal strikes on boats and hinting at land operations in Venezuela, slides the United States closer to outright conflict with no transparency, oversight or apparent guardrails,” she said.

The Trump administration is yet to provide underlying evidence to lawmakers proving that the boats targeted by the US military were in fact carrying narcotics, according to two US officials familiar with the matter.

AP