The US military carried out a lethal strike on a vessel in the eastern Pacific, killing four people, according to defense secretary Pete Hegseth.

In a post on Twitter/X, Hegseth wrote: “Joint Task Force Southern Spear conducted a lethal kinetic strike on a vessel operated by a Designated Terrorist Organizations in international waters. Intelligence confirmed that the vessel was transiting along a known narco-trafficking route in the Eastern Pacific and was engaged in narco-trafficking operations. A total of four male narco-terrorists were killed, and no US military forces were harmed.”

The announcement comes a day after Donald Trump announced a blockade of all sanctioned oil tankers entering and leaving Venezuela. In announcing the blockade on social media, the US president accused Venezuela of using oil to fund drug trafficking and other crimes and vowed to escalate the military buildup.

On Tuesday, the Pentagon said it had carried out strikes on three boats it accused of trafficking drugs in the Pacific, killing eight people. Since 2 September, more than 20 strikes have killed at least 99 people, most off the coast of Venezuela.

The administration has faced increasing pressure to release video of a 2 September vessel attack, but Hegseth has refused to do so and the administration has defended its efforts as a success, saying it has prevented drugs from reaching US shores, and pushed back on concerns that it is stretching the bounds of lawful warfare.

The administration has also said the campaign is about stopping drugs headed to the US, but Trump’s chief of staff, Susie Wiles, appeared to confirm in a Vanity Fair interview published Tuesday that the campaign is part of a push to oust Venezuela’s president, Nicolás Maduro.

Wiles said Trump “wants to keep on blowing boats up until Maduro cries uncle”.