Libyan leader Muammar Qaddafi is not close to a military breaking point despite nearly two weeks of coalition strikes that have degraded his fighting power, the top U.S. military officer told Congress on Thursday.

The comments by Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, came amid concerns in Washington that the United States might deepen its involvement in Libya, where poorly organized rebels are struggling against better armed loyalist forces.

Fears of mission creep have been heightened by revelations that President Barack Obama has signed an order authorizing covert U.S. support for rebel forces. 

U.S. Defense Secretary Robert Gates declined comment on any CIA role in Libya, but assured Congress that the United States had no plans to send in ground forces or expand the military mission to include ousting Qaddafi from power.

"Deposing the (Qaddafi) regime, as welcome as that eventuality would be, is not part of the military mission," Gates said in testimony to the House of Representatives Armed Services Committee.

Mullen testified alongside Gates that coalition strikes had taken a toll on Qaddafi's overall forces, but signaled a long struggle ahead.

"We have actually fairly seriously degraded his military capabilities ... We've attrited his overall forces at about the 20- to 25-percent level," Mullen said.

"That does not mean he's about to break from a military standpoint, because that's not the case."

WHO WILL TRAIN REBELS?

A day after a headlong rebel retreat set off alarms in Washington, Gates and Mullen portrayed a Libyan rebel force that counted perhaps only 1,000 militarily trained fighters.

Gates acknowledged the rebels, of whom U.S. officials have very limited knowledge, lacked training and organization. But he played down the odds the U.S. might step in to assist them.
"In terms of providing that training, in terms of providing assistance to them, frankly, there are many countries that can do that," Gates said.

"That's not a unique capability for the United States. And, as far as I'm concerned, somebody else should do that."

Gates, who has openly speculated about cracks within the Qaddafi regime, predicted political and economic measures would ultimately pave the way for Qaddafi's ouster, over time, by his own people.

To that end, the White House cheered the defection of Libyan Foreign Minister Moussa Koussa, saying it delivered a "significant blow" to Qaddafi. It urged Qaddafi's other aides to "get on the right side of history."