US airstrikes on alleged drug-trafficking boats in the Caribbean Sea are an act of tyranny, Colombia's President Gustavo Petro told the BBC in an interview where he also called for criminal proceedings against US officials if investigations find Colombians were killed in the attacks.

President Donald Trump has cast the strikes, which have reportedly killed 17 since they began this month, as necessary to stop the flow of fentanyl and other illegal narcotics into the US.

Legal experts and lawmakers, though, have questioned if they violate international human rights laws.

Why launch a missile if you could simply stop the boat and arrest the crew? said Petro. That's what one would call murder.

Speaking to the BBC on Wednesday, Petro asserted there should be zero deaths in efforts to stop speedboats suspected of drug smuggling. We have a long history of collaborating with American agencies and other agencies in maritime seizures of cocaine. No one has ever died before. There is no need to kill anyone, he insisted.

He also contended that the principle of proportionality of force is violated if you use anything more than a pistol.

The US strikes in international waters have primarily focused on Colombia's neighbour Venezuela, according to the Trump administration, but the US has provided little detail about the targets and the individuals killed.

Democratic lawmakers in Washington are demanding answers from the White House regarding the legality of these strikes, which United Nations experts have described as extrajudicial executions.

When asked about Petro's comments, the White House stated that Trump was prepared to use every element of American power to stop drugs from flooding into our country and to bring those responsible to justice.

In the interview, conducted in New York amidst the annual high-profile United Nations meeting, Petro accused the Trump administration of humiliating his nation and insisted that South American countries like Colombia would not bow down to the king.

After returning to office in January, Trump has toughened his rhetoric and trade policies concerning all of Latin America and is conducting a significant deportation sweep against individuals he claims have crossed the US southern border illegally.

He has also designated several drug-trafficking organizations and criminal groups across Latin America as terrorist organizations, intensifying military actions in the region.

Petro has faced ongoing tensions with Trump, responding to allegations of isolation and asserting that it is Trump's foreign policies that are isolating the United States.

Trump had already insulted me during a presidential campaign; he called me a terrorist, he remarked.