San Francisco  - US comedian and Oscar winner Robin Williams is to undergo surgery to replace a heart valve, his representatives told the US celebrity magazine People.

Williams, 57, was admitted to a southern Florida hospital this week with shortness of breath and broke off a tour of his one-man comedy show Weapons of Self-Destruction.

Doctors ordered him to take a rest, but Williams' spokesmen told People Thursday that his 80-city tour, which began in September and was to go to New York's Broadway in the spring, would resume in the autumn.

"This tour has been amazing fun, and I can't wait to get back out on the road after a little tune-up," the performer who won the best supporting actor Oscar in 1997 for Good Will Hunting said in a statement.

The date of Williams' surgery to replace his aortic valve was not announced.

Heart valves are replaced when they fail to open or close properly. The aortic valve regulates the flow of blood from the heart's left ventricle into the aorta, which distributes blood to the rest of the body.

The surgery is the same undergone this week by former first lady Barbara Bush, wife of former president George HW Bush and mother of former president George W Bush.

Williams began his entertainment career as a stand-up comic and became a household name when he played an extraterrestrial in the television comedy Mork and Mindy in the late 1970s and early '80s.

He has since taken a mixture of comic and dramatic film roles and received Oscar nominations for 1987's Good Morning Vietnam, 1989's Dead Poets Society and 1991's The Fisher King. (dpa)