Foreign ministers meet in Qatar on Wednesday for talks on Libya's future, with some eager to step up air strikes against Muammar Gaddafi's forces, fearing the conflict could settle into a bloody stalemate.
The international "contact group" will hear from representatives of the rebel national council based in eastern Libya, who show little sign so far of being able to dislodge the veteran leader from power in Tripoli despite the air campaign.
Nor, after the collapse this week of an African Union-sponsored peace plan, was there any sign of compromise between the warring sides.
Libyan government spokesman Mussa Ibrahim lashed out against the West's "imperialist way of thinking," accusing world powers of trying to impose political change on Libya.
"We are ready to fight if it's necessary. Not the Libyan army but every man and woman and every tribe in Libya," he said in Tripoli late on Tuesday.
Moussa Koussa, a former Libyan foreign minister who fled to Britain last month, will meet rebels in Doha on the sidelines of the contact group talks, the British government said on Tuesday.
The contact group meeting comes amid reports of a deepening humanitarian crisis in the besieged, rebel-held western city of Misrata.
"It is not acceptable that Misrata is still under fire and being bombarded by Gaddafi's troops," French Foreign Minister Alain Juppe said in Luxembourg on Tuesday.
NATO took over air operations from a coalition of the United States, Britain and France on March 31 and the rebels have accused it of not doing enough.
Insurgents said renewed artillery bombardments and heavy fighting hit Misrata on Tuesday. They said they had beaten back two government offensives but civilians remained under fire and short of food and medicines.
Juppe said NATO must stop Gaddafi shelling civilians and take out the heavy weapons bombarding the city. "NATO must play its role fully," he said.
Speaking after meeting European Union foreign ministers in Luxembourg later, Juppe said the alliance should "exert the most efficient military pressure. We need to be more efficient."
British Foreign Secretary William Hague said NATO countries should "intensify our efforts" and urged others to follow London in providing additional ground-strike aircraft.
NATO, which is operating under a U.N. mandate to protect civilians, rejected criticism.
"NATO is conducting its military operations in Libya with vigor within the current mandate. The pace of the operations is determined by the need to protect the population," it said.
Late on Tuesday, the alliance said its aircraft had destroyed five tanks close to Misrata. "Our aircraft will continue to hit regime targets around Misrata," NATO operation commander Lieutenant-General Charles Bouchard said in a statement.
U.S. ROLE "RECEDES"
Britain and France, Europe's two main military powers, are carrying out most of the air strikes on Gaddafi's armor since President Barack Obama ordered U.S. forces to take a back seat. The Americans are providing intelligence, logistical support and air-to-air refueling, but not bombing.
Two U.S. officials, speaking on condition that they not be identified, said Washington's position had not shifted. But they added that some military assets unique to the U.S. military -- probably A-10 Warthog ground-attack aircraft or AC-130 gunships -- could be brought to bear on Gaddafi's heavy weaponry.
The Pentagon said on Tuesday however that NATO had not asked the United States to intensify its military operations.
"We feel like we've contributed a great deal to the success of this operation thus far," State Department spokesman Mark Toner said. "Our role has receded in this mission."
The range of views among the 28 members of the NATO alliance is wide. Germany, Turkey and Poland opposed the Libya operation and are not involved in the air campaign.
Italy has said its aircraft will not open fire, the Dutch are enforcing the no-fly zone but may not bomb ground targets and non-NATO Swedish planes may only open fire in self-defense while patrolling the no-fly zone.
A Reuters/Ipsos MORI poll found most people in Britain, Italy and the United States felt their country could not afford military action, while a majority in all countries polled except France felt NATO action in Libya did not have clear objectives.
Libyan rebels have sent a request for weapons they need to countries that have recognized their national council as the sole representative of Libya, a spokesman in Benghazi said.
France, Italy and Qatar have recognized the rebels. Qatar has been marketing oil from rebel-held Libya.