WASHINGTON — The Obama administration demanded Friday that Moammar Gadhafi's forces immediately begin retreating from opposition-controlled areas in east Libya, as Britain and France rushed to enforce the world's demand for the Libyan regime to halt violence against civilian protesters and rebels seeking Gadhafi's ouster.

Secretary of State Hillary Rodham Clinton said the U.S. wasn't impressed by the Libyan government's claim of a cease-fire, saying "we would have to see action on the ground — and that is not yet at all clear."

President Barack Obama summoned congressional leaders to the White House to confer on Libya and Obama planned to make a statement on the crisis later Friday.

Clinton said the first goal of international action is to end the violence in Libya and that the regime's forces need to pull back "a significant distance away from the east, where they have been pursuing their campaign against the opposition."

The larger objective remains Gadhafi's ouster.

Clinton's comments came after the administration and America's allies won an open-ended endorsement Thursday from the United Nations for military action in Libya, where Gadhafi's regime has led a bloody campaign to suppress dissent and eliminate any opposition to his 42-year rule.

The breakthrough at the U.N. Security Council came after days of cautious diplomacy from the administration and set the stage for airstrikes, a no-fly zone and other military measures short of a ground invasion to halt the violence in Libya and push Gadhafi from power.

Britain said Friday it will send Typhoon and Tornado fighter jets to air bases "in the coming hours" to prevent Gadhafi's forces from mounting air strikes against the rebels. France has also spoken on swift action, while Italy announced that it will allow its military bases to be used for the U.N.-backed military intervention.

The U.S. hasn't revealed what role it will play, but it has a vast array of naval and air forces in the region, some positioned there in recent weeks for a possible response to the fighting and resulting humanitarian crisis.

Among ships the U.S. has in the Mediterranean area are the nuclear-powered submarine USS Providence, equipped with Tomahawk missiles; the amphibious landing dock USS Ponce and amphibious assault ship USS Kearsarge, with a contingent of 400 Marines and dozens of helicopters; the command ship USS Mount Whitney and destroyers USS Mason, USS Barry and USS Stout.

The U.S. backing for international action comes after several administration officials questioned the plan for providing aerial cover, with the Pentagon perhaps the most vocal in its skepticism. It has described the no-fly zone as a step tantamount to war, and a number of U.S. officials have expressed fears that involvement in Libya could further strain America's already stretched military and entangle the country in an expensive and messy conflict in another Muslim country.

Clinton said the U.N. Security Council's 10-0 vote authorizing military action "sent a strong message that needs to be heeded," and that Gadhafi's refusal to hear the repeated calls for him to stop the bloodshed had forced the world to pursue military action.

Gadhafi "cannot continue his violence against his own people," she said after a meeting with Ireland's foreign minister. "He cannot continue to attack those who started out peacefully demonstrating for changes."

Clinton said the U.S. had seen the reports of a cease-fire by the Libyan government, but added that "we are going to be not responsive or impressed by words." She said the immediate objective of any intervention was to halt the violence against civilians, but insisted that the "final result of any negotiation would have to be the decision by Col. Gadhafi to leave."

Just Thursday, speaking in Tunisia, Clinton spoke cautiously about the possibility of a no-fly zone, saying it would require action to protect the planes and pilots, "including bombing targets like the Libyan defense systems." But pressed on by Britain and France, and buoyed over the weekend by the surprise support of the Arab League, the no-fly option gained traction.

After the resolution, Obama spoke with French President Nicolas Sarkozy and British Prime Minister David Cameron and the leaders "agreed that Libya must immediately comply with all terms of the resolution and that violence against the civilian population of Libya must cease," according to a White House statement.

Even before the Security Council's 10-0 vote, the Obama administration readied plans to enforce the no-fly zone, with congressional officials describing a closed-door briefing in which the administration said it could ground Gadhafi's air force by Sunday or Monday. The effort likely will involve jet fighters, bombers and surveillance aircraft, officials said, and the U.S. is keen to have Arab countries such as Jordan, Qatar and the United Arab Emirates participate in the operation.

Five nations abstained on the vote, including Russia and China. But the fact that neither exercised their right to veto the resolution represented a major victory for the U.S. and its allies, who've often been stymied at the global body by countries fearful of granting powers that infringe on national sovereignty.

For Obama, the shift to international action arrived as he faced increased criticism for not moving aggressively enough to help the rebels trying to topple Gadhafi, long counted as among the world's most ruthless rulers. Some U.S. lawmakers demanded the no-fly zone, while others have proposed more strident measures such as supplying the opposition with arms.

Three leading senators applauded the U.N. action.

"The administration deserves credit for getting this resolution passed with such strong support," said a joint statement from Democratic Sen. John Kerry, Republican Sen. John McCain, and independent Sen. Joe Lieberman. "This was an important step on behalf of the people of Libya, but it will only be as effective as its implementation. With Gadhafi's forces moving toward Benghazi, we must immediately work with our friends in the Arab League and in NATO to enforce this resolution and turn the tide before it is too late."

The senators said they would also work to build bipartisan support for Obama to take "decisive measures to stop Gadhafi."