Former New York Mayor Ed Koch, the combative politician who rescued the city from near-financial ruin during three City Hall terms, has died at age 88.

Spokesman George Arzt says Koch died Friday morning of congestive heart failure.

In City Hall, Koch embodied New York for the rest of the world. He won a national reputation with his feisty style and his trademark question, "How'm I doing?"

During his years as mayor, from 1978 to 1989, his tight fiscal policies pulled the city out of severe financial difficulties. But homelessness and racial tensions soared and critics charged that City Hall's responses were ineffective.

His mark on the city was set in steel when the Queensboro Bridge, connecting Manhattan to Queens, was renamed in Koch's honour in 2011.