Fueling a spat that has shattered ties between the two nations, Gustavo Petro said, "Mr Trump has slandered me and insulted Colombia."

He insisted Trump was "carrying out extrajudicial executions" that "violate international law" by striking alleged drug-trafficking boats.

Colombia has urged Washington to halt the strikes, which have destroyed nine vessels and killed at least 37 people, according to US figures.

At least one Colombian is among the dead, a fisherman who Petro said may have become involved in trafficking "intermittently" to escape poverty.

The pushback has infuriated Trump, who has branded Petro a "thug" and drug trafficker.

Trump also announced cuts to US aid to Colombia and threatened tariffs on Colombian goods.

If enacted, the cuts would effectively end decades of security cooperation to curb the flow of cocaine from the world's biggest producer, Colombia, to its biggest consumer, the United States.

But on Thursday, Petro dismissed the impact of cutting aid, saying the cash goes to fund US non-governmental groups and to buy US arms.

"What happens if they take away the aid? In my opinion, nothing," he said.

Petro said Trump's decision to put Colombia on a blacklist of countries not helping in the drug war was an "insult."

He insisted Colombia was successfully countering cartels, despite cocaine production and exports hitting record levels.

"We have been the most effective in cocaine seizures in world history," said Petro.

Petro said Trump was being fed misinformation by his opponents on Colombia's "far right."

He said they aimed to influence Colombia's 2026 presidential election, to "strike Colombian progressivism and seize oil wells" in Venezuela.

US Secretary of State Marco Rubio has called Petro a "lunatic."

Colombia has recalled its ambassador from Washington and called for dialogue.