Libyan leader Moammar Gadhafi, increasingly cornered under a stunning upturn in NATO airstrikes, lashed back with renewed shelling of the western city of Misrata Wednesday, killing 10 rebel fighters.

The international alliance said it remained determined to keep pounding Gadhafi forces from the air, but would play no military role in the transition to democratic rule in oil-rich North African country once the erratic leader's 42-year rule was ended.

In Brussels, NATO Secretary-General Anders Fogh Rasmussen said Gadhafi's days in power were clearly numbered, making it imperative for the international community, the United Nations in particular, to gear up to help Libyans establish a new form of government.

"For Gadhafi, it is no longer a question of if he goes but when he goes," Fogh Rasmussen said at a meeting of the defense ministers from the 28 members of the North Atlantic military alliance.

"We do not see a lead role for NATO in Libya once this crisis is over," he said. "We see the United Nations playing a lead role in the post-Gadhafi, post-conflict scenario."

The alliance said it was acting in the skies over Libya purely in accordance with the U.N. mandate to protect the Libyan people from Gadhafi. The resolution did not include any involvement in post-conflict peacekeeping.