The United States began carrying out such strikes -- which experts say amount to extrajudicial killings even if they target known traffickers -- in early September, taking aim at vessels in the Caribbean and eastern Pacific.

The US strikes have destroyed at least 18 vessels so far -- 17 boats and a semi-submersible -- but Washington has yet to make public any concrete evidence that its targets were smuggling narcotics or posed a threat to the United States.

Hegseth released aerial footage on X of the latest strike, which he said took place in international waters like the previous strikes and targeted "a vessel operated by a Designated Terrorist Organization."

The video showed a boat traveling through the water before exploding into flames.

"Three male narco-terrorists -- who were aboard the vessel -- were killed," Hegseth said, without any further identifying information.

"To all narco-terrorists who threaten our homeland: if you want to stay alive, stop trafficking drugs. If you keep trafficking deadly drugs -- we will kill you," he wrote.

Like some previous videos released by the US government, a section of the boat is obfuscated for unspecified reasons.

President Donald Trump's administration has built up significant forces in Latin America, in what it says is its campaign to stamp out drug trafficking.

So far it has deployed six Navy ships in the Caribbean, sent F-35 stealth warplanes to Puerto Rico, and ordered the USS Gerald R Ford carrier strike group to the region.

The governments and families of those killed in the US strikes have said many of the dead were civilians -- primarily fishermen.

Venezuela's President Nicolas Maduro has repeatedly accused Trump of seeking to oust him.

US bombers have also conducted shows of force near Venezuela, flying over the Caribbean Sea off the country's coast on at least four occasions since mid-October.

Maduro -- who has been indicted on drug charges in the United States -- insists there is no drug cultivation in his country, which he says is used as a trafficking route for Colombian cocaine against its will.

The Trump administration has said in a notice to Congress that the United States is engaged in "armed conflict" with Latin American drug cartels, describing them as terrorist groups as part of its justification for the strikes.

The United Nations has asked the United States to cease its campaign, with rights chief Volker Turk saying the killings have taken place "in circumstances that find no justification in international law."