US President Barack Obama, hoping to hand over US command of Libya operations to allies within days, agreed with UK Prime Minister David Cameron and French President Nicolas Sarkozy that NATO would play a key role, the White House said.
But the allies stopped short of endorsing NATO political leadership of the mission, which would be difficult for alliance member Turkey to accept and undercut shaky Arab support for the effort to protect Libyans from Muammar Gaddafi's forces.
France has called for a "political steering body" including Arab countries to take charge of the no-fly zone operation.
Obama, under domestic pressure to limit US involvement, said he had "absolutely no doubt" a deal would be reached soon and that the operation's costs could be managed despite a push for budget cuts by his Republican political opponents.
"The American people are going to feel satisfied that lives were saved and people were helped," Obama said at a news conference in El Salvador, the final stop of a Latin America tour.
Later in a CNN interview, Obama said Gaddafi may try to wait out the no-fly zone and military assault but that Western allies would not let up on the Libyan leader.
"Gaddafi may try to hunker down and wait it out even in the face of the no-fly zone, even though his forces have been degraded," Obama said. "We don't just have military tools at our disposal in terms of accomplishing Gaddafi's leaving. We put in place strong international sanctions. We've frozen his assets. We will continue to apply a whole range of pressure on him.
In Brussels, NATO agreed on Tuesday to enforce an arms embargo on Libya and completed plans to enforce a UN-mandated no-fly zone if needed. But French and Turkish objections again prevented any deal to put the operation under NATO command.
Obama's diplomatic push, in phone calls to Cameron, Sarkozy and other leaders, underscored his eagerness to put a non-U.S. face on the campaign against Gaddafi's forces, even if US military might remains the backbone of the operation.
A senior US official said the allies were working to bring in both NATO and non-NATO partners and voiced hope that more Arab countries, including Saudi Arabia and the United Arab Emirates, would soon announce contributions to the effort.
The question of who takes over leadership of the Libya mission is crucial for Obama, who has stressed limited US involvement for both voters and lawmakers worried about US forces becoming bogged down in another Muslim country while still occupied in Iraq and Afghanistan.
French Foreign Minister Alain Juppé said foreign ministers of countries taking part in military action in Libya were set to meet in the coming days to create a clear political structure for operations.
"I've proposed with the agreement of our British colleagues that we set up a political structure to guide operations, involving foreign ministers from countries that are taking part and from the Arab League," Juppé told the French parliament.
"Once we have this political structure [...] we will naturally use the planning and intervention capacities of NATO," he said.
A NATO official said the fact the 28-nation alliance had agreed on a detailed operations plan for a no-fly zone was significant. "However, that doesn't take into account the political reality of having to reach agreement on whether to execute it," the official said.
That agreement has thus far proved hard to find. While Obama, Cameron and Sarkozy agreed NATO's command structure could be used to support the coalition, French and Turkish objections continued to throw a question mark over the future structure of the alliance.
France, which launched the first strikes on Libya, has argued against a prominent role for NATO, citing the US-dominated alliance's poor reputation in the Arab world. Turkey has said the air strikes have already gone beyond what had been sanctioned by the UN Security Council.
Other NATO states, most vocally Italy, say NATO should either have command or no role at all.
Gaddafi's forces attacked two west Libyan towns on Tuesday, killing dozens of people while rebels pinned down in the east struggled themselves to create a command structure that can capitalise on the allied help.
'Transfer within a few days'
The UN Security Council resolution authorizing the action on Libya passed by a 10-0 vote, but Russia and China, among five nations that abstained, have voiced doubts about the campaign, echoed by other emerging powers such as India and Brazil.
US Defence Secretary Robert Gates told reporters in Moscow he still saw a quick handover.
"I don't want to get out in front of the diplomacy that's been going on but I still think that a transfer within a few days is likely," Gates told reporters on a visit to Russia.
Opinion polls show mixed US public support for the Libya campaign as some members of Congress step up criticism of Obama. Some lawmakers say he waited too long to get involved. Others say Obama has failed to define the mission in Libya and warn about sending stretched US forces into a third war.
Obama, who will return from a trip to Latin America on Wednesday, telephoned the Turkish and Qatari leaders on
"I do believe the Turks have largely resolved the questions they had before," the senior US official said. "We're confident that you are going to see more Arab participation than you've seen already."
One UN Security Council diplomat said on condition of anonymity that Turkey and United Arab Emirates were considering participating in the Libya operations by patrolling the port of Benghazi to ensure it remained open for humanitarian deliveries.
(EurActiv with Reuters.)