US secretary of state Hillary Clinton has made it clear Washington believes any decision to impose a no-fly zone over Libya is a matter for the United Nations and should not be a US-led initiative.
Yesterday, Muammar Gadafy's tanks and warplanes pounded rebel positions in Zawiyah, the closest rebel-held city to the capital, Tripoli.
Rising casualties and threats of hunger and a refugee crisis have increased pressure on foreign governments to act, but many were fearful of moving from sanctions alone to military action.
"We want to see the international community support it [a no-fly zone]," Mrs Clinton told Sky News. "I think it's very important that this not be a US-led effort."
She said the United Nations should make the decision on Libya, not the United States. "We've called for Colonel Gadafy to leave," she added. "When a leader turns against his own people, that is the end."
US president Barack Obama and British prime minister David Cameron agreed the "common objective" was an end to violence and the departure of Col Gadafy, the White House said.
In a phone call, the two leaders "agreed to press forward with planning, including at Nato, on the full spectrum of possible responses, including surveillance, humanitarian assistance, enforcement of the arms embargo, and a no-fly zone."
Britain and France are seeking a UN resolution to authorise such a zone to ground Col Gadafy's aircraft and prevent him moving troops by air. Russia and China, which have veto power in the UN Security Council, are cool towards the idea, which would be likely to require bombing of Libyan air defences.
Hafiz Ghoga, spokesman for the rebel National Libyan Council, told a news conference in the rebel base of Benghazi in eastern Libya: "We will complete our victory when we are afforded a no-fly zone. If there was also action to stop him [Gadafy] from recruiting mercenaries, his end would come within hours."
In besieged Zawiyah, 50km west of Tripoli, trapped residents sheltered from the onslaught of goverenment tanks and aircraft.
Reached by phone in the early hours of today, a resident called Ibrahim told Reuters: "Zawiyah as you knew it no longer exists. They have been attacking the town from 10 in the morning until 11.30 in the evening."
He said there were dozens of bodies in the street, adding: "There is no electricity, no water and we are cut off from the outside world."
Reuters