TRIPOLI, Libya - (AP) - Moammar Gadhafi struck a defiant stance Thursday after two high-profile defections from his regime, saying the Western leaders who have decimated his military with airstrikes should resign immediately.

Gadhafi's message was undercut by its delivery - a scroll across the bottom of state TV as he remained out of sight. The White House said the strongman's inner circle was clearly crumbling with theloss of Foreign Minister Moussa Koussa, who flew from Tunisia toEngland on Wednesday.

Ali Abdessalam Treki, a former foreign minister and U.N. GeneralAssembly president, announced his departure on several oppositionwebsites the next day, saying "It is our nation's right to live infreedom and democracy and enjoy a good life."

Gadhafi attempted to appear undaunted, accusing the leaders ofthe countries attacking his forces of being "affected by powermadness."

"The solution for this problem is that they resign immediately and their peoples find alternatives to them," the Libya state news agency quoted him as saying.

His government's forces appeared to have retaken some momentum on the rapidly moving front line of the battle with oppositionforces, retaking the town of Brega after pushing the rebels milesback toward the territory they hold in eastern Libya.

The rebels said they were undaunted, taking heart from thedepartures in Gadhafi's inner circle.

"We believe that the regime is crumbling from within,"opposition spokesman Mustafa Gheriani said in Benghazi, the rebels'de facto capital.

He compared Gadhafi to a wounded animal.

"An injured wolf is much more dangerous than a healthy wolf.But we hope the defections continue and I think he'll find himselfwith no one around him," Gheriani said.

Most high-level Libyan officials are trying to defect but areunder tight security and having difficulty leaving the country,said Ibrahim Dabbashi, the deputy ambassador in Libya's U.N.mission, which now backs the opposition.

Koussa is privy to all the inner workings of the regime, so hisdeparture could open the door for some hard intelligence, thoughBritain refused to offer him immunity from prosecution.