Former New York City Mayor Rudy Giuliani has been ​hospitalised and is in “critical but stable condition,” ‌his spokesperson said on Sunday.

The spokesperson, Ted Goodman, did not immediately provide more details about Giuliani’s condition or how ​long he has been hospitalised.

“Mayor Giuliani is ​a fighter who has faced every challenge ⁠in his life with unwavering strength, and he’s ​fighting with that same strength now,” Goodman said in ​a statement.

“We do ask that you join us in prayer for America’s Mayor Rudy Giuliani.”

Giuliani, 81, garnered acclaim for ​his response to the September 11, 2001, attack on New York City, earning the nickname “America’s Mayor.”

Giuliani ‌worked ⁠as an attorney for President Donald Trump in his failed efforts to overturn the results of the 2020 election, an effort that led to criminal ​charges against ​Giuliani in ⁠two US states and a defamation lawsuit from election workers.

Giuliani has denied ​wrongdoing in the criminal cases.

Trump, in ​a ⁠social media post, called Giuliani the “Best Mayor in the History of New York City” and said he ⁠had ​been mistreated by Democrats.

“What a tragedy that he was treated so badly by the Radical Left Lunatics, Democrats ALL — AND HE WAS RIGHT ABOUT EVERYTHING!” Trump wrote.

“They cheated on the Elections, fabricated hundreds of stories, did anything possible to destroy our Nation, and now, look at Rudy. So sad!”

Giuliani was previously ​hospitalised last year following a car crash in New Hampshire.