Tripoli:
NATO jets on Sunday began enforcing the no-fly zone in Libya, Secretary-General Anders Fogh Rasmussen announced. Diplomats said the full transfer of authority would take several days.
NATO will assume command of all aerial operations in Libya from the US-led force that has been conducting air strikes against Moammar Gadhafi's forces, officials said on Sunday.
"NATO allies have decided to take on the whole military operation in Libya under the UN Security Council resolution," Fogh Rasmussen said in a statement.
"NATO will implement all aspects of the UN resolution. Nothing more, nothing less."
The North Atlantic Council - the alliance's top body - took two hours to approve a plan to expand a previously agreed mission to enforce the UN Arms embargo and no-fly zone.
It agreed to protect civilians from attack - which effectively means bombing Gadhafi's forces if they are threatening to harm the civilian population.
The UN authorised the operation after Gadhafi launched attacks against anti-government protesters who demanded that he step down after 42 years in power
"In the past week, we have put together a complete package of operations in support of the United Nations resolution by sea and by air," Fogh Rasmussen said.
After eight days of strikes on Libyan targets, Washington is eager to quickly hand off responsibility for the air offensive to the alliance.
US President Barack Obama and Defence Secretary Robert Gates have both said that American command of the military operations in Libya would last only a few days.
Gates has said that major strides are being made in bolstering rebels, but acknowledged the international operation could drag on for months.
NATO officials said the alliance's operations, approved for up to three months, could be extended if necessary.
The air strikes have already tipped the balance away from Gadhafi's regular military to the lightly armed rebels, although the two sides remain at stalemate in key cities.
A Canadian three-star general, Charles Bouchard, will be in charge of all NATO operations.
He will report to an American admiral, Samuel Locklear, commander of NATO's Allied Joint Force Command Naples.
Naples is one of NATO's two operational headquarters. The other, Brunssum in the Netherlands, is responsible for the war in Afghanistan.
The Naples centre will coordinate the radar surveillance planes, aerial refuelling tankers, maritime patrol aircraft and helicopters needed to maintain the operation 24 hours a day.
NATO has significant experience in such operations. Its warplanes successfully enforced a no-fly zone over Bosnia in the early 1990s and bombed Serbian forces in Kosovo in 1999 in an effort to end crackdowns on ethnic Albanian civilians.