Libyan leader Muammar Gaddafi.

Washington - Libya's Muammar Gaddafi will “never run the country again,” US Senator John Kerry insisted on Friday, although he urged patience over the embattled strongman's departure from power.

Washington last month announced it would recognise the rebels in the five-month civil war as Libya's de facto government, and US lawmakers have pressed for an American embassy in the rebel-held east of the country, but a defiant Gaddafi has so far refused to leave power in Tripoli.

“Gaddafi will never run the country again under any circumstances whatsoever,” Kerry told US broadcaster MSNBC, hours after rebels said a NATO air strike killed Gaddafi's youngest son Khamis and 31 other people.

That claim has been sharply denied by the authorities in Tripoli.

Despite several blows to his regime and being slapped with an International Criminal Court arrest warrant for crimes against humanity, Gaddafi has clung to power in defiance of the NATO air strikes in support of rebels.

Members of Gaddafi's inner circle have made proposals for democratic elections in recent months but have been dismissed by international powers including the United States.

Kerry stressed that Western forces “have prevented slaughter from taking place in a number of communities (in Libya) and we've given these folks an opportunity to decide their future, particularly those who are pressing for democracy and for rights.”

But he urged patience in getting Gaddafi to step down, pointing to how it took former Serbian strongman Slobodan Milosevic “a full year before he left” after the NATO bombings in Serbia.

“I think we have to learn to be patient. The pressure is real. I believe ultimately Gaddafi will leave,” Kerry said. - Sapa-AFP