Updated

NATO agreed late Thursday to take over part of the military operations against Libya — enforcement of the no-fly zone — after days of hard bargaining among its members. But the toughest and most controversial portion of the operation — attacks on the ground — will continue to be led by the U.S., which has been anxious to give up the lead role.

NATO Secretary-General Anders Fogh Rasmussen, who announced the agreement in Brussels, said the alliance could eventually take more responsibility, "but that decision has not been reached yet." It appeared that some NATO members balked at any involvement in attacks on ground targets, something the alliance's sole Muslim member, Turkey, has resisted.

In Washington, Secretary of State Hillary Rodham Clinton praised NATO for taking over the no-fly zone, even though the U.S. had hoped the alliance would take full control of the military operation authorized by the United Nations, including the protection of Libyan civilians and supporting humanitarian aid efforts on the ground. The operation cost the U.S. close to $1 billion in less than a week, and has drawn criticism in Congress from members of both parties.

NATO said late Thursday that it expected to commence enforcement of the no-fly zone within two to three days. The operation will be commanded from Naples by Adm. Samuel J. Locklear.

NATO also agreed to launch military planning for a broader mandate, including a "no-drive" zone that would prevent Libyan leader Moammar Gadhafi's armor and artillery from moving against rebels his forces had been routing before the coalition's air assault began late last week.

"If we are led to hit tanks, it is because the tanks target the civilians," French President Nicolas Sarkozy said, adding that Gadhafi troops stationed tanks in neighborhoods to provoke civilian casualties.

The North Atlantic Council is scheduled to meet on Sunday to consider the broader plans.

"Without prejudging deliberations, I would expect a decision in coming days," Fogh Rasmussen said.

Diplomats also have drawn up plans to put political supervision of NATO's effort in the hands of a broader international coalition. U.S., European, and Arab and African officials have been invited to London next week to work out the details.

"The political coordination cannot be only NATO because there are countries there that are not members of NATO," Sarkozy said.

U.S. weapons are being used less frequently than they were when airstrikes began. French fighter jets used deep inside Libya on Thursday hit aircraft and a crossroads military base.

"Nearly all, some 75 percent of the combat air patrol missions in support of the no-fly zone, are now being executed by our coalition partners," Navy Vice Adm. William Gortney, told reporters Thursday at the Pentagon. Other countries were handling less than 10 percent of such missions Sunday, he said.

The U.S. will continue to fly combat missions as needed, but its role will mainly be in support missions such as refueling allied planes and providing aerial surveillance of Libya, Gortney said.

Allies have especially sought military assistance from Arab countries, seeking to avoid an all-Western military presence. Qatar is expected to begin flying air patrols this weekend, and on Thursday Clinton praised a second Arab nation, the United Arab Emirates, after it agreed to deploy 12 planes.

NATO's top decision-making body, the North Atlantic Council, had been struggling for six days to reach an agreement on using its military command and control capability to coordinate the operation in Libya.

Senior Obama administration officials said the breakthrough came in a four-way telephone call with Clinton and the foreign ministers of Britain, France and Turkey. The four worked out the way forward, which included the immediate transfer of command and control of the no-fly zone over Libya, and by early next week of the rest of the U.N.-mandated mission.

The officials, speaking on condition of anonymity to discuss sensitive military planning, said the actual handover of the no-fly zone would occur in one or two days.

Turkey's parliament on Thursday authorized the government to participate in military operations in Libya, including the no-fly zone.

Libya's air force has been effectively neutralized. Briefing reporters in Tripoli late Thursday, Libyan Deputy Foreign Minister Khaled Kaim said no Libyan planes have been in the air since the no-fly zone was declared.

But the rebels demanding Gadhafi's ouster after 42 years in power remain less organized and less heavily armed than Gadhafi's forces, and they have had trouble taking full advantage of the international airstrikes. A U.N. arms embargo blocks the rebels and the government from getting more weapons.

The rebels were so strapped Thursday that they handed out sneakers — and not guns — at one of their checkpoints.

"We are facing cannons, T-72 and T-92 tanks, so what do we need? We need anti-tank weapons, things like that," said Col. Ahmed Omar Bani, a military spokesman told reporters in Benghazi, the de facto rebel capital.

The airstrikes may have prevented Gadhafi from quickly routing the rebels, whose control extends mainly to eastern portions of Libya. But the weakness of both sides could mean a long struggle for control of the country, and international support is not open-ended: French Foreign Minister Alain Juppe said the international action would last days or possibly weeks, but not months.

Representatives for the regime and rebels were expected to attend an African Union meeting in Addis Ababa, Ethiopia, on Friday, according to U.N. Secretary-General Ban Ki-moon, who described it as a part of an effort to reach a cease-fire and political solution.

Ban said Gadhafi has ignored U.N. demands to declare a cease-fire and risks further Security Council action if he doesn't halt the violence. In his report to the 15-member council, Ban expressed concerns about Libya's precarious humanitarian situation, protection of civilians, and human rights abuses.

U.N. human rights experts said hundreds of people have disappeared in Libya over the past few months, and said there were fears that those who vanished were taken to secret locations to be tortured or executed. Luis Moreno-Ocampo, the International Criminal Court's prosecutor, said he was "100 percent" certain that his investigation into attacks on Libyan protesters will lead to crimes against humanity charges against the Gadhafi regime.

Ban, taking questions from reporters after the Security Council meeting, insisted that the resolutions intend to protect Libya's civilian population, not push Gadhafi from power.

"The primary aim is to provide protection for civilians, to save lives," Ban said. "It's not aiming to change any regime."

Sarkozy also said Gadhafi would not necessarily have to step down for the operation to end. "It is when Gadhafi forces go back to their barracks and the civilians would no longer be threatened," that the U.N. mandate would be completed, he said.

The French airstrikes hit a base about 250 kilometers (155 miles) south of the Libyan coastline, as well as a Libyan combat plane that had just landed outside the strategic city of Misrata, France's military said.

Kaim, the Libyan foreign minister, said no Libyan planes have flown since the no-fly zone began but that a plane might have been destroyed in an allied attack on an air base.

Kaim said earlier that the "military compound at Juffra" was among the targets hit. Juffra is one of at least two air bases deep in Libya's interior, on main routes that lead from neighboring countries in the Sahara region that have been suppliers of arms and fighters for the Gadhafi regime.

___

AP writers Robert Burns and Erica Werner in Washington, Ryan Lucas in Benghazi, Libya, Hadeel Al-Shalchi in Tripoli, Libya, Ben Hubbard and Maggie Michael in Cairo, Jamey Keaten in Paris, Anita Snow at the United Nations, Suzan Fraser in Ankara and Alessandra Rizzo in Rome contributed to this report.