In a CNN interview, the Argentine leader, Javier Milei, called Colombian President Gustavo Petro a "murdering terrorist".

He also said the Mexican president was "ignorant".

Mr Milei is infamous for his colourful language and abrasive rhetoric.

While personal attacks are not uncommon in Latin American politics, Mr Milei surprised many when he attacked Pope Francis last year, calling the pontiff "an imbecile who defends social justice".

While the Pope dismissed the remarks and the two men embraced during a meeting at the Vatican, Latin American politicians have not been as forgiving.

Pope Francis laughed off Mr Milei's comments

The CNN interview which has caused the latest stir will be broadcast on Sunday, but the channel has released some clips ahead of transmission.

In one of them, Mr Milei suggests that Colombia under left-wing President Petro could deteriorate and come to resemble Venezuela and Cuba.

"In Venezuela, there's carnage, it's truly unprecedented, same as on that prison island, Cuba," he tells CNN's Andrés Oppenheimer.

"And there are others who're going down that road, such as Colombia with Mr Petro," he adds.

"Well, you can't expect much from someone who was a murdering terrorist, right?" he asks in an apparent reference to Mr Petro's past as a former rebel fighter.

Mr Petro was a member of the now disbanded M-19 guerrilla group in the 1980s.

As part of its war against the Colombian state, the group stormed the Palace of Justice in the Colombian capital, Bogotá, in 1985, and held more than 300 people hostage.

The security forces lay siege to the building and more than 100 people died in the ensuing battle to retake it from the M-19. The incident is known as "28 hours of terror" in Colombia.

But while Mr Petro was a member of the M-19 guerrilla group, he did not take part in the attack on the Palace of Justice. He was in jail at the time for his involvement with the group.

President Petro and his Argentine counterpart are poles apart politically and have clashed in the past

Mr Petro has never made a secret out of his past inside the M-19, which demobilised more than 30 years ago.

As Colombia's first left-wing president, he has come in for plenty of criticism at home, but there has been widespread outrage in the Andean country over the comments made by Mr Milei.

The foreign ministry said Mr Milei had offended President Petro's "dignity" and said it would expel a number of Argentine diplomats, without specifying how many.

In Mexico, the two candidates vying to replace President Andrés Manuel López Obrador as president in the election in June also came to his defence.

They demanded that the Argentine leader treat Mr López Obrador with respect after Mr Milei said in the CNN interview that the fact that the "ignorant" Mexican president had spoken badly of him only flattered him.

Mr López Obrador has in the past labelled Mr Milei "a fascist ultra-conservative".