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.

US figures show it has destroyed 10 vessels and killed at least 43 people in under two months.

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.

Washington is also deploying an aircraft carrier strike group to counter drug-trafficking organisations in Latin America, the Pentagon said Friday, a major increase to a military build-up in the region that is fuelling fears of war.

The deployment of the USS Gerald R Ford and accompanying ships "will enhance and augment existing capabilities to disrupt narcotics trafficking and degrade and dismantle [transnational criminal organisations]," Pentagon spokesman Sean Parnell said in a statement.

The Ford, which was commissioned in 2017, is America's newest aircraft carrier and the world's largest, with more than 5,000 sailors aboard. (AFP)