The U.S. military has fatally struck another alleged drug trafficking boat in international waters off the coast of Venezuela, President Donald Trump said on Tuesday.

The strike killed six people aboard the boat.

In a message on social media, President Trump claimed the boat was confirmed to have narcotics aboard and was "associated with illicit narcoterrorist networks." He said the boat was using a route known as a corridor for "designated terrorist organizations."

This is the fifth such fatal U.S. strike against boats in the Caribbean, as President Trump's administration continues what it calls a "non-international armed conflict" against alleged drug smugglers.

Earlier this month, a memo from the White House to Congress designated drug cartel officials "unlawful combatants" engaged in an "armed conflict."

According to reporting from The Associated Press, the Pentagon has not yet provided a list of designated terrorist organizations that it purports to be targeting with the strikes.

RELATED STORY | Trump declares drug cartels operating in Caribbean unlawful combatants

House Speaker Mike Johnson defended the president’s authority to carry out the drone strikes, saying the cartels are “at war with us” through fentanyl trafficking.

But lawmakers, including both Democratic and Republican senators, have questioned the Trump administration's use of force and legal standing to deploy military forces in such a manner.