Published: Mar 31, 2011 5:23 PM EDT
Updated: Mar 31, 2011 2:24 PM EDT

WASHINGTON- As the U.S. debates its future role in the Libyan conflict, Defense officials slammed the brakes on any broad participation Thursday, with Defense Secretary Robert Gates saying there will be no American ground troops in Libya "as long as I am in this job."

Under withering congressional probing and criticism of an ill-defined mission to aid a rebel force that officials know little about, Gates and Joint Chiefs chairman Adm. Mike Mullen sketched out a largely limited role for the U.S. military going forward, with Gates saying some other country could train the rebels trying to oust strongman Moammar Gadhafi.

"My view would be, if there is going to be that kind of assistance to the opposition, there are plenty of sources for it other than the United States," said Gates. "Somebody else should do that."

Asked by one lawmaker whether the U.S. involvement might inevitably mean "boots on the ground" in Libya, Gates replied, "Not as long as I am in this job."

The U.S. turned over control of the military operation to NATO Thursday, just hours before Gates and Mullen told Congress that future U.S. participation will be limited and will not involve an active role in airstrikes as time goes on.

They were unable; however, to answer key questions from clearly agitated lawmakers about the length of the operation and how it will play out if Gadhafi does not relinquish power.

The U.S. goals are unclear and officials don't know who the rebels are, said Rep. Mike Turner, R-Ohio, adding that if it came to a vote he would not support U.S. involvement in the operation.

He and others repeatedly complained that Congress has not been consulted on the Libya operation, and chafed that the legislative branch is not willing to be a backseat driver.

Gates and Mullen insisted that Libyan leader Moammar Gadhafi's military has been degraded by as much as 25 percent, but Mullen noted that regime forces still outnumber the rebels by about 10-to-1.

Meanwhile, they said the opposition groups are fractured and operating independently city by city, and just 1,000 of the rebels are militarily trained.

Their comments came as Gadhafi's forces struck forcefully back at the rebels this week, recapturing lost ground and triggering pleas for help from the battered and failing opposition forces.

Gates said that he believes political and economic pressures will eventually drive Libyan leader Gadhafi from power, but the military operation will help force him to make those choices by degrading his defense capabilities.

Gates and Mullen testifed before the House and Senate Armed Services Committees in the wake of new revelations that small teams of CIA operatives are working in Libya.

Gates declined to comment on the CIA activities in Libya.

U.S. officials have acknowledged that the CIA has sent small teams of operatives into Libya and helped rescue a crew member of a U.S. fighter jet that crashed.

The CIA's precise role in Libya is not clear. Intelligence experts said the CIA would have sent officials to make contact with the opposition and assess the strength and needs of the rebel forces in the event President Barack Obama decided to arm them.

Meanwhile, battlefield setbacks are hardening the U.S. view that the poorly equipped opposition probably is incapable of prevailing without decisive Western intervention, a senior U.S. intelligence official told The Associated Press.

The administration says there has been no decision yet about whether to arm the opposition groups, and acknowledged that the U.S. needs to know more about who the rebels are and what role terrorists may be playing there.

Rep. Adam Smith of Washington state, the top Democrat on the House Armed Services Committee, said the U.S. must better explain to the American public that this is not an open-ended conflict and that the U.S. will not become embroiled in a civil war.

Committee chairman Rep. Howard "Buck" McKeon, R-Calif., said he has concerns about U.S. objectives in Libya.

"History has demonstrated that an entrenched enemy like the Libyan regime can be resilient to airpower," McKeon said.

 (Copyright 2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)