NATO allies are savouring a bittersweet achievement in Libya: while the air campaign appears close to victory, the mission exposed major frailties in their ability to carry out a fight.

While Libya's new regime battles to defeat the last forces loyal to deposed dictator Moamer Kadhafi, NATO defence ministers will draw lessons from the six-month mission during talks Wednesday and Thursday.

With one conflict drawing to an end, the 28-nation alliance will also take stock of the war in Afghanistan, which marks 10 years on Friday amid plans by NATO allies to withdraw combat troops by 2014.

"Our operation to protect civilians (in Libya) has been a great success," said NATO Secretary General Anders Fogh Rasmussen.

While the mission is "close to an end," the ministers will not terminate it this week because Kadhafi forces are still attacking civilians, he told a news conference on Monday.

NATO warplanes prevented Kadhafi from crushing a rebellion that erupted in February while daily bombing runs left the fugitive former leader's military in tatters, allowing the ragtag rebel army to take over the country in August.

It is also the first NATO operation with Europeans in the driver's seat while the United States took a backup role.

But Operation Unified Protector revealed shortcomings within the 28-nation alliance, with some allies refusing to participate while those who did relied heavily on the United States for key intelligence and logistics support.

Only eight NATO states took part in bombing missions -- France, Britain, Canada, Belgium, Denmark, Norway, Italy and the United States -- while Germany and Poland irked allies by staying out of the fight.

"Our wish is that, when a similar operation presents itself, a higher number of European allies will have the desire and capabilities to intervene," the French ambassador to NATO, Philippe Errera, told reporters. "But these remain national decisions."

Europeans are under pressure from the United States to avoid drastic cuts in defence spending but a debt crisis is forcing governments to impose austerity programmes that have not spared armies.

"Our engagements in Libya and Afghanistan showed areas where allies must continue to improve their capabilities, such as drones, intelligence and air-to-air refuelling," Rasmussen said.

"We cannot count on one ally to provide these assets," said the NATO chief, referring to the United States.

The US military is facing its own budgetary constraints, under orders from President Barack Obama to find about $350-400 billion (265-300 billion euros) in cuts over the next 10 years.

"The time and era in which Europe could rely on the United States to do everything, that era, if it ever existed, is now clearly coming to a close," said a senior NATO diplomat who spoke on condition of anonymity.

In a parting shot to European allies, Robert Gates warned in June before retiring as US defence minister that their cutbacks risked driving NATO towards a "dismal" future. His successor, Leon Panetta, is expected to deliver a softer message when he attends his first NATO ministerial meeting this week, an alliance diplomat said.

Despite the deep gaps between the United States and Europe, defence analyst Jan Techau said the Libyan operation could serve as a blueprint for what NATO will look like in the future.

NATO can become a more flexible and pragmatic alliance, with some nations staying out of operations, like Germany and Poland chose to do, while the military club could serve as a vehicle to pool and share capabilities.

"NATO will be different, but it will not come to and end," said Techau, director of Carnegie Europe think tank.