Hundreds of armed anti-government forces backed by military defectors who control the city closest to the capital Tripoli prepared Sunday to repel an expected offensive by forces loyal to Moammar Gadhafi surrounding Zawiya.

Two prominent U.S. Senators said Washington should recognize and arm a provisional government in rebel-held areas of eastern Libya and impose a no-fly zone over the area — enforced by U.S. warplanes — to stop attacks by the regime. U.S. Secretary of State Hillary Rodham Clinton echoed President Barack Obama's demand for Gadhafi to relinquish power.

"We want him to leave," she told reporters traveling with her Sunday to a U.N. meeting on Libya planned for Monday. "We want him to end his regime and call off the mercenaries and forces loyal to him. How he manages that is up to him."

Gadhafi's son, Seif al-Islam, claimed again that the country was calm and denied the regime used force or airstrikes against its own people. But human rights groups and European officials have put the death toll since unrest began in Libya nearly two weeks ago at hundreds, or perhaps thousands, though it has been virtually impossible to verify the numbers.

There were no reports of violence or clashes on Sunday.