The Trump administration has said the strikes were meant to stop the flow of drugs into the US and increase pressure on Venezuelan President Nicolás Maduro.
The US military said it struck another boat suspected of smuggling drugs in international waters in the eastern Pacific on Monday, killing one person.
At the direction of US Secretary of Defence Pete Hegseth, "Joint Task Force Southern Spear conducted a lethal kinetic strike on a low-profile vessel operated by Designated Terrorist Organisations in international waters," the US Southern Command wrote in a post on X.
"Intelligence confirmed the low-profile vessel was transiting along known narco-trafficking routes in the eastern Pacific and was engaged in narco-trafficking operations," it added.
The strike brought the total death toll to 105 across 29 operations.
The vessel strike campaign began on 1 September when US forces attacked a boat in the Caribbean, killing 11 people. Trump announced the operation the following day, claiming the vessel was carrying drugs bound for the United States.
The campaign has drawn scrutiny from lawmakers and legal experts who question whether the operations comply with US and international law.
Some critics argue that the use of lethal force in international waters without due process amounts to extrajudicial killing.
Trump and other top US officials have repeatedly dismissed the allegations as unfounded.
The administration formally notified Congress on 1 October that the US was engaged in a "non-international armed conflict" with drug cartels, designating those killed as "unlawful combatants".
The notification cited a classified US Justice Department determination authorising lethal strikes without judicial review.
The US president has designated Venezuela's government a "foreign terrorist organisation" and accused Maduro of using oil revenues to finance drug trafficking, human trafficking and terrorism.
Maduro denies the allegations and accuses Washington of seeking regime change.