Britain and France joined the U.S. on Wednesday in saying they’re willing to consider arming Libyan rebels, as opposition forces beat a full retreat from the key Libyan oil port of Ras Lanuf.

British Prime Minister David Cameron said he’s certain there is a legal loophole to allow nations to supply weapons to Libya’s rebels — but stressed the U.K. has not decided whether it will offer assistance.

“We do not rule it out, but we have not taken any decision” on whether to supply equipment, he told the House of Commons.

French Foreign Minister Alain Juppe made similar remarks after a London meeting on Libya.

“I remind you it is not part of the U.N. resolution, which France sticks to, but we are ready to discuss it [arming the rebels] with our partners,” Juppe told reporters.

U.S. Secretary of State Hillary Clinton told an international summit on Libya in London on Tuesday that the U.N. resolution would allow nations to circumvent a current arms embargo.

Rebels Routed In Ras Lanuf

NATO has intervened in the Libyan conflict with near daily airstrikes to weaken the regime’s superior military power vis-a-vis the poorly trained and badly equipped ragtag rebel army.

Rebel fighters retreated Wednesday from Ras Lanuf along the coastal road leading to the capital Tripoli after they came under heavy shelling from ground forces loyal to leader Moammar Gadhafi.

NATO planes flew over the zone where the heaviest fighting was under way, and an Associated Press reporter at the scene heard explosions, indicating a new wave of airstrikes against Gadhafi’s forces.

U.S. Marine Corps Capt. Clint Gebke, a spokesman for the NATO operation aboard the USS Mount Whitney, said he could not confirm any specific strikes, but said that western aircraft were engaging pro-Gadhafi forces.

“The joint task force is still supporting the civilians on the ground via sorties,” he said in a telephone interview.

A rebel near the front lines told the AP that the opposition fighters withdrew from Ras Lanuf rather than fighting the regime forces that were closing in on them.

With the help of NATO airstrikes earlier in the week, rebel who control the eastern half of Libya rapidly advanced westward on the main coastal highway that leads to Gadhafi’s stronghold in the capital. They got within 60 miles of the city of Sirte, Gadhafi’s hometown and a bastion of support for the longtime leader with a major military base.

At that point, they came under heavy bombardments by regime ground forces that outgun the rebels in every way — in numbers, equipment and training.

Over the past two days, the poorly organized rebel forces have been in full retreat back eastward on the coastal highway, with no help from NATO airstrikes that they had pleaded for until around midday Wednesday.

Rebel forces have now been driven back from an attempted assault on Sirte for the second time in weeks. The last time, early in the month, it nearly meant the end of their movement: They retreated hundreds of miles west and Gadhafi forces nearly stormed their capital, Benghazi, until the U.S. and European strikes began 10 days ago, driving Gadhafi’s forces back from bloody sieges.

NPR’s Lourdes Garcia-Navarro, reporting from Tripoli, said Wednesday that rebels in the east were extremely upset that NATO aircraft didn’t bomb Gadhafi’s positions and that they have had to make a full retreat.

“These rebels are ill-equipped, ill-trained; they don’t have a lot of weaponry. And rebels will tell you that without airstrikes, they simply would have lost not only Ras Lanuf, Ajdabiya and Brega, but Benghazi itself,” Garcia-Navarro said.

Gadhafi Has ‘Lost The Legitimacy To Lead’

At the London summit, world leaders agreed that Gadhafi should step down but have yet to decide what additional pressure to put on him.

“Gadhafi has lost the legitimacy to lead, so we believe he must go. We’re working with the international community to try to achieve that outcome,” Clinton told reporters after the talks concluded.

German Foreign Minister Guido Westerwelle said it “has to be made very clear to Gadhafi: His time is over.” But Germany and other countries have expressed reservations about the current military intervention in Libya, let alone expanding it.

Britain’s Cameron stressed that “the Libyan people cannot reach that future on their own. … We are all here in one united purpose: that is to help the Libyan people in their hour of need.”

Clinton said the international community must support calls for democracy sweeping Libya and its neighbors, but warned that “these goals are not easily achieved.” U.S. Ambassador to the United Nations Susan Rice said there are plenty of “non-military means at our disposal” to oust the Libyan leader.

Italian Foreign Minister Franco Frattini pushed a plan for a cease-fire, exile for Gadhafi and a framework for talks on Libya’s future between tribal leaders and opposition figures. He said negotiations on securing his exit were being conducted with “absolute discretion,” though he said there could be no promise of immunity for Gadhafi from international prosecution. So far, Gadhafi has shown little sign he might choose exile, vowing to fight to the end.

Cameron and Sarkozy urged Gadhafi loyalists to seize a final chance to abandon him and side with those seeking political reform — effectively pinning hopes on a palace coup.

Representatives of the opposition’s political leadership, the Interim National Council, met Tuesday with Clinton and Hague but did not attend the main conference.

Mahmoud Shammam, a council spokesman, suggested Libyans were prepared to fight their own battle. Though the international community had a responsibility to prevent “mass genocide,” he told reporters, “We are not asking for any non-Libyan to come and change the regime.”

“The aspirations of the Libyan people are to be free, to live under a constitutional democratic system,” Shammam said. “[We have] had enough of tyranny.”

A senior Obama administration official said the U.S. would soon send an envoy to Libya to meet with rebel leaders.

Chris Stevens, former U.S. envoy to Tripoli, will travel to the rebel stronghold of Benghazi in the coming days to establish better ties with groups seeking to oust the longtime Libyan leader. The official, who spoke on condition of anonymity to discuss internal planning, stressed that the move doesn’t constitute formal recognition of the opposition.

In the more densely inhabited western half of the country, Gadhafi has largely crushed the rebellion in Tripoli and in several towns that rose up against his rule since the turmoil began Feb. 15. Other towns and cities in the west never saw an effective anti-Gadhafi uprising, suggesting his popular support there is stronger, or that tribes in those areas chose to stay neutral to see who wins the conflict.

Regime forces continued to besiege the last significant rebel holdout in the west, Libya’s third-largest city, Misrata. From Misrata’s outskirts, the troops pounded streets and the city’s port, residents said. At least three people were killed in shelling Monday, a doctor in the city said.

With reporting from NPR’s Lourdes Garcia-Navarro in Tripoli. Material from The Associated Press was used in this story. Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.