NATO's commander for the naval blockade of Libya said Thursday he expected he would have enough ships to effectively prevent weapons and mercenaries from entering Libya, but said he was still in a "build-up phase" and that it was impossible to patrol the entire coast.

Vice Adm. Rinaldo Veri of Italy held a first briefing at NATO's base in Naples a day after the alliance's vessels began patrols, a tangible sign NATO was taking command of some coalition operations for Libya while negotiations continued over whether it would take over enforcing the no-fly zone as well.

Veri said the Mediterranean was the "easiest, fastest and most direct" way to get weapons into Libya and that it was impossible to patrol its entire coast. But he said the start of maritime patrols Wednesday using NATO's ships currently in the region was "closing the main front door."

He said he expected to have enough vessels in place in a few days for effective operations.

Veri declined to say how many ships he had at his disposal or how many had been pledged, saying only that contributions had come from Italy, Britain, Greece, the United States, Canada, Spain and Turkey. On Wednesday, NATO officials in Brussels said the alliance had received offers for up to 16 vessels.

"We are expecting many contributions from the nations," Veri said. "And I confide that in a few days time we will have enough assets to carry out effectively the operation and even sustain it in the medium period."

Turkey alone offered four frigates and a submarine. Turkey wants NATO to assume the command but insists that the rules of engagement be restricted to protecting civilians, enforcing the arms embargo and no-fly zone, and the provision of humanitarian aid. This would exclude any further air strikes against Libyan leader Moammar Gadhafi's ground forces.

The U.N. Security Council imposed the arms embargo last month to prevent weapons, ammunition, tanks and spare parts _ as well as foreign mercenaries _ from entering Libya to support Gadhafi's loyalists. More than two weeks later, it imposed a no-fly zone that coalition forces began enforcing on Saturday.

Italy, which has offered seven of its military bases for use by coalition aircraft, has insisted the full operation shift to NATO's command, and has said NATO's Naples base, which houses the alliance's joint command for maritime, air and land forces in the region, should serve as headquarters.

Officials stressed Thursday that NATO's maritime unit, which is responsible for enforcing the naval blockade, was conducting the briefing and not the broader alliance. The briefing was held at the joint force base because it can accommodate more people than at the maritime headquarters on the tiny island of Nisida off the coast, officials said.

Veri said one day into the mission, NATO vessels hadn't intercepted any suspect ships. But he said NATO forces were prepared to send armed forces onto boats that don't voluntarily submit to inspections.

"If they should find resistance, the use of force is necessary," he said, noting that the Security Council had mandated all means necessary to enforce the embargo.