Libyan military officials say revolutionary forces could capture former leader Moammar Gadhafi's hometown of Sirte within days.

A Defense Ministry spokesman, Colonel Ahmed Bani, said Wednesday that provisional government fighters have surrounded the strategic coastal city. A local commander said his forces have gained control of half the town. But another National Transitional Council official said an all-out assault on Sirte has been delayed to allow residents to flee.

Gadhafi loyalists inside the city have mounted fierce resistance during three weeks of intense fighting. The battle has come at a high cost for civilians, many of whom have been trapped by the clashes with dwindling supplies of food and water and no proper medical supplies to treat the wounded.

Sirte's capture would be highly significant as NTC leaders have vowed to step down after the city is secured and the country's liberation declared. Such an outcome would be necessary for NATO to complete its air mission over Libya.

NATO defense ministers meeting in Brussels Wednesday and Thursday are discussing how and when to end the six-month campaign. NATO Secretary-General Anders Fogh Rasmussen said the decision will hinge on the ability of NTC forces to maintain order, and not the fate of Mr. Gadhafi, whose whereabouts are unknown.

U.S. Defense Secretary Leon Panetta told the NATO meeting the Libya campaign has exposed “gaps” in the alliance's capabilities. Panetta said the issues include a shortage of drones , refueling tanks and intelligence specialists.

He said that while U.S. assistance is needed, the Libya mission shows European nations can successfully take the lead role in NATO operations.