Donald Trump has accused French President Emmanuel Macron of “kissing Xi Jinping’s a**” during his recent visit to Beijing.
Mr Macron held talks with his Chinese counterpart last week in the hope of convincing him to use his relationship with Russia’s Vladimir Putin to end the war in Ukraine.
Speaking to Fox News on Wednesday, the former US president was asked about the trip.
He said: “You’ve got this crazy world that’s blowing up and the United States has absolutely no say.
“And Macron, who’s a friend of mine, is over with China kissing his [Xi’s] ass in China. I said ‘France is now going to China?'”
Mr Trump, who recently became the first former US president to face criminal charges, had an increasingly strained relationship with Mr Macron as his time in office went on.
An Elysee Palace spokesperson has described Mr Trump’s comments as “vulgar”.
It comes after Mr Macron faced a major backlash for saying Europe should avoid getting involved in any US-China confrontation over Taiwan.
The French president told reporters from Politico and Les Echos on the plane back from Beijing that it would be a “trap” for Europe to get caught up in “crises that are not ours”.
Instead, he said Europe’s focus should be on “strategic autonomy”.
“Do we [Europeans] have an interest in speeding up on the subject of Taiwan? No. The worst of things would be to think that we Europeans must be followers on this subject and adapt ourselves to an American rhythm and a Chinese overreaction,” he told journalists.
Backlash in US and Europe
In the US, Republican senator Marco Rubio said in a tweet that if Europe planned to opt out of the diplomatic crisis over Taiwan, the US should rethink its support of peace in Europe.
“Maybe, we should basically say we are going to focus on Taiwan and the threats that China poses, and you guys handle Ukraine and Europe,” he posted.
One European MEP contested that Mr Macron only speaks for France – not the rest of the bloc.
Mr Macron travelled to China with European Commission President Ursula von der Leyen.
He told Mr Xi: “Russian aggression in Ukraine has dealt a blow to [international] stability. I know I can count on you… to bring Russia to its senses and bring everyone back to the negotiating table.”
“We need to find a lasting peace,” Mr Macron said. “I believe that this is also an important issue for China, as much as it is for France and for Europe.”
Mr Xi failed to mention Russia or Ukraine in his response, but said he was committed to a relationship with France.
In his Fox News interview, Mr Trump praised the Chinese leader.
“President Xi is a brilliant man: if you went all over Hollywood to look for somebody to play the role of President Xi, you couldn’t find him,” he said.
Mr Trump is next due in court over alleged hush money to support his 2016 election campaign later this year.