The Obama administration on Tuesday urged Libyan leader Moammar Gadhafi to concede defeat and tell his loyalists to stop fighting, as rebels overran his compound in Tripoli and his power appeared to evaporate. The call came as U.S. officials said they hoped to free up as much as $1.5 billion in frozen Gadhafi regime assets to give to the opposition.
Defense Secretary Leon Panetta said that while the situation remained uncertain Gadhafi foes had made "significant gains." He hoped that NATO operation in Libya, which he said had been an important part of the opposition's success, would soon be ending.
"Hopefully that is a mission that is beginning to draw to a close," Panetta told a packed auditorium at the Naval Postgraduate School in Monterey, Calif., near his hometown of Carmel. "The opposition forces have obviously made significant gains, but the situation obviously remains very fluid."
Panetta praised the NATO mission to protect Libyan civilians for having contributed to the rebels' progress.
"We have protected civilians, we've established a no fly zone and we have worked with our NATO partners in going after a kind of important support and assistance that was, I think, part of the key in helping opposition forces there ultimately be able to succeed," he said.
U.S. defense officials said that NATO forces will continue to strike targets of opportunity, if given the needed information and intelligence that regime forces are present. But they are exercising caution to prevent any civilian casualties.
There have been routine strikes in Tripoli in recent weeks, particularly with precision guided missiles that can zero in on small targets. But as rebel forces pour into the city, it has become more difficult to insure that no innocent civilians would be hurt.
Officials said that the military has some general ideas on where regime forces are in the city, but in most cases they are not making their presence known.
The U.S. officials spoke on condition of anonymity to describe military operations.
In Washington, the State Department said Gadhafi should accept and publicly declare that his 42-year reign is over.
"There's no question that the Gadhafi regime has nearly collapsed," spokeswoman Victoria Nuland told reporters. "There's also no question that the best thing he could do for his people would be to relinquish power immediately."
"What the Libyan people are looking for, what the international community is looking for is a reliable, affirmative statement, not only to the Libyan people and international community but to his own loyalists, that he understands this is over, that he understands that the days of his leadership are over, so that everybody can move on to have the democratic, strong, united Libya that they deserve," she said.
Nuland also said the U.S. hoped to soon give the opposition between $1 billion and $1.5 billion in frozen Gadhafi regime assets to help it meet immediate humanitarian needs. That amount represents about half of the Gadhafi regime's liquid assets that have been frozen in the United States. The vast majority of the about $37 billion in frozen assets in the U.S. is in real estate and other property holdings.
The money _ expected to be a first payment _ will be released once the U.N. sanctions committee gives its approval, something the U.S. hopes will happen in the coming days.
Associated Press writers Matthew Lee and Lolita C. Baldor in Washington contributed to this report.