The United States on Friday announced sanctions on Colombia's President Gustavo Petro, who Washington has accused of failing to curb illicit drug trafficking, alongside his wife and son.

"President Petro has allowed drug cartels to flourish and refused to stop this activity," said US Treasury Secretary Scott Bessent in a statement unveiling the move.

"President (Donald) Trump is taking strong action to protect our nation and make clear that we will not tolerate the trafficking of drugs into our nation," he added.

The sanctions come amid a growing spat between Petro and Trump, with Colombia's leader accusing his US counterpart of "carrying out extrajudicial executions" that "violate international law" by striking alleged drug-trafficking boats.

The US has destroyed 10 vessels and killed at least 43 people in under two months, according to an AFP tally based on US figures.

Colombia has demanded that Washington halt the attacks, infuriating Trump, who has branded Petro a "thug" and drug trafficker.

Trump, in turn, also announced an end to hundreds of millions of dollars of US aid to Colombia and threatened tariffs on Colombian goods.

On Friday, Petro issued a defiant response to news that he and his family were placed on a US sanctions list.

"Not one step back and never on my knees," Petro posted on social media, echoing slogans used by Latin American revolutionaries.

Petro was sanctioned on justifications relating to the international proliferation of illicit drugs or their means of production.

During a media briefing on Thursday, White House Press Secretary Karoline Leavitt told reporters that Washington was not "seeing de-escalation from the unhinged leader of Colombia right now."