Former New York City Mayor Rudy Giuliani has been hospitalized and is in "critical but stable condition," his spokesperson, Ted Goodman, said in a statement Sunday.

"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. "We do ask that you join us in prayer for America's Mayor Rudy Giuliani."

There was no immediate reason given for the 81-year-old's hospitalization. 

This is a breaking news story. It will be updated.