A senior NATO official is warning that the issue of resources will become critical if operations against Libyan leader Moammar Gadhafi were to last long.

But French General Stephane Abrial, a senior NATO commander, said Tuesday that NATO so far has the means necessary to carry out its mission in the North African country wracked by violence.

The general made his comments to reporters during a NATO military conference in Belgrade, Serbia.

A day earlier, the head of Britain's Royal Navy, Admiral Mark Stanhope, warned that the British fleet might not be able to sustain the scale of its operations off the Libyan coast in the long term without cutbacks elsewhere.

Also last week, outgoing U.S. Defense Secretary Robert Gates said the Libyan operation pointed out the alliance's shortcomings and called on NATO partners to meet their obligations to the alliance.

During this ongoing debate on resources, top NATO officials are meeting in Belgrade for a military conference.

The conference opened a day after Serb nationalists led angry protests against the military alliance in part for its 1999 air raid on the city aimed at stopping Serbia's crackdown on ethnic Albanian separatists in Kosovo.

The Serbian government is hoping to set a date for the start of negotiations with the European Union for Serbia's membership in the bloc. It got closer to that goal after delivering a top war crimes suspect, Bosnian Serb wartime commander Ratko Mladic, to the international war crimes tribunal in The Hague last month.

Serbian nationalists are angry about Mladic's extradition. The former general is facing charges of genocide against some 8,000 Bosnian Muslims, but is seen as a heroic defender of Serbian interests by his supporters.