Former NYC Mayor Rudy Giuliani was hospitalized and is in critical condition, a spokesperson for the former mayor said on Sunday.

“Mayor Rudy Giuliani is currently in the hospital, where he remains in critical but stable condition,” Giuliani spokesperson Ted Goodman posted on social media shortly before 7 p.m.

“Mayor Giuliani is a fighter who has faced every challenge in his life with unwavering strength, and he’s fighting with that same level of strength as we speak.”

Goodman did not elaborate on what sent Giuliani, 81, to the hospital.

Giuliani was mayor of New York City during the September 11 attacks on the World Trade Center, serving from 1994 to 2001. He has emerged in recent years as a close ally of President Trump.