Trump announced the strike on Tuesday, claiming the targeted boat was linked to drug trafficking.
“Under my Standing Authorities as Commander-in-Chief, this morning, the Secretary of War ordered a lethal kinetic strike on a vessel affiliated with a Designated Terrorist Organization (DTO),” Trump wrote on social media.
“The strike was conducted in International Waters, and six male narcoterrorists aboard the vessel were killed in the strike. No US Forces were harmed,” he added.
Trump did not provide evidence to support the claim that the boat was conducting drug trafficking.
As with earlier strikes, he shared a video appearing to show a stationary small vessel before being hit by a US missile.
The latest attack is the fifth known US bombing in the Caribbean Sea.
Human rights groups and legal experts have called such actions violations of international law, noting that suspected drug traffickers do not meet the definition of armed combatants.
Despite legal concerns, the operations have continued for over a month.
The first strike occurred on September 2, killing 11 people.
Subsequent attacks on September 15 and 19 left three dead each, while an October 3 strike killed four, according to US Defense Secretary Pete Hegseth.
The total death toll now stands at 27.
Officials have described the operations as efforts to stop “narco-terrorists” from reaching the United States, though it remains unclear who was aboard the vessels or what they carried.
Critics argue the attacks highlight Trump’s growing use of executive power with limited oversight.
In August, reports surfaced that Trump had secretly authorized military action against drug-trafficking networks.
A subsequent memo to Congress in early October stated that the United States was engaged in a “non-international armed conflict” with drug cartels, labeling them “unlawful combatants.”
The move builds on the administration’s campaign to classify narcotics groups as “foreign terrorist organizations,” which rights advocates warn could justify military action abroad.
Last week, the US Senate rejected a Democratic-backed bill that sought to require congressional approval for future strikes on suspected drug-trafficking vessels.
The attacks come amid a broader US military buildup in the Caribbean, including deployments to bases in Puerto Rico.
The increase has fueled speculation about possible action against Venezuela, whose president, Nicolas Maduro, remains a frequent target of Trump’s criticism.
At a White House news conference Tuesday, Trump repeated unsubstantiated claims that Venezuela was sending criminals to the United States.
“We get drugs and all of that, but we get something, in a way, worse,” he said.
“What they do very well is they send their criminals into the United States, and they send Tren de Aragua.”
A declassified US intelligence report in May found no evidence linking Maduro to the Tren de Aragua gang or its activities in the United States.