High-profile defections put pressure on Gadhafi

>>> good evening. it is the third front americans are fighting tonight, and tonight the libya story is on the move. there have been some important developments during the day today. first, reports of some sort of a deal possibly in the works to get gadhafi out of there, but his army is still fighting hard, still not letting those rebels advance. despite the u.s. having fired off 227 cruise missiles and flying all those countless air missions. and tonight with nato now in charge of the fight, the air war , the no-fly zone, the u.s. has announced it will no longer fly combat air missions over libya starting tomorrow. we want to begin tonight with nbc's jim maceda who remains inside tripoli for us. jim , good evening.

>> reporter: hi, brian. even as moammar gadhafi 's forces gain the upper hand against the rebels on the battlefield, his regime is beginning to show signs of collapse from within. these rebels have come full circle . their drive towards tripoli began here in ajdabiya a week ago but they have been driven all the way back to where they started. outgunned and outsoldiered they still dream of taking sirte, gadhafi 's hometown, hundreds of miles away . i tell you by 6:00 p.m . we'll be in sirte, says this rebel, but not tonight. instead the opposition's governing council offered a cease-fire if gadhafi stepped down and pulled his forces back from all of libya 's cities. gadhafi , who hasn't been seen in ten days, rejected the cease-fire terms. still, political pressure on the regime is mounting. today another high-profile defection rocked tripoli . libya 's new u.n. ambassador quit, saying too much blood had been spilled in libya . that on the heels of moussa koussa's defection, gadhafi 's foreign minister and key adviser who is now in great britain being debriefed by british intelligence . and even members of gadhafi 's family, including his son, may be seeking a way out as well. publicly defiant as in this recent interview with nbc news --

>> this is our country. we live here and we die here.

>> reporter: but british media speak of secret meetings in london between his top aide and british officials. and just how spooked is gadhafi about a possible flood of defections? well, the government has now assigned security guards to shadow each and every major government official just in case. brian.

>> jim maceda inside tripoli . jim , thanks for your reporting tonight.