Former New York mayor Rudy Giuliani is hospitalized in "critical but stable condition," his spokesman said Sunday, without specifying the nature of the 81-year-old former lawyer's health problems.

"Mayor Giuliani is a fighter who has faced every challenge in his life with unwavering strength, and he is fighting today with that same level of determination," added Ted Goodman, his spokesman, on X.

He did not specify the name of the facility where the former elected official is being treated, nor the date of his hospitalization, but called for prayers for "America's mayor, Rudy Giuliani".

The New York Times reported that he is hospitalized in Florida.

This tough former prosecutor, who had made a name for himself by hitting the New York mafia hard and praised for his handling of the aftermath of the September 11, 2001 attacks, had failed in the Republican primary for the presidential nomination in 2008.

But Donald Trump's former personal lawyer fell from grace in 2023 when he was ordered to pay $148 million in damages for defamation amid allegations of election fraud in the 2020 presidential election.

Mr. Giuliani had played a leading role in the campaign to try to invalidate the results of the presidential election which had been won by Democrat Joe Biden.

He has since been disbarred in New York and Washington.

Last November, he was among the 77 people involved in the attempt to overturn the results of the 2020 presidential election and was pardoned by Donald Trump.

The American president praised Mr. Giuliani as a "true warrior", and the best mayor in the history of New York, in his opinion.

"What a tragedy that he was treated so badly by the radical left lunatics, ALL Democrats — AND HE WAS RIGHT ABOUT EVERYTHING!", Mr. Trump added about his former White House chief of staff.

"They cheated in the election, fabricated hundreds of stories, did everything possible to destroy our nation and now look at Rudy. So sad!" he continued.