The Obama administration has sent teams of CIA operatives into Libya in a rush to gather intelligence on the identities and capabilities of rebel forces opposed to Libyan leader Moammar Gaddafi, according to U.S. officials.

The information has become more crucial as the administration and its coalition partners move closer to providing direct military aid or guidance to the disorganized and beleaguered rebel army.

Although the administration has pledged that no U.S. ground troops will be deployed to Libya, officials said Wednesday that President Obama has issued a secret finding that would authorize the CIA to carry out a clandestine effort to provide arms and other support to Libyan opposition groups.

The officials, who spoke on the condition of anonymity, insisted that no decision has been made.

In the face of a new onslaught by government troops, rebel forces fled eastward Wednesday from cities and towns they had captured just days ago. But Gaddafi suffered a political defeat with the defection to Britain of his foreign minister, Musa Kusa, the most senior official to break ranks since the coalition bombing campaign began nearly two weeks ago.

House and Senate lawmakers briefed in a closed-door session by top administration officials, including Secretary of State Hillary Rodham Clinton and Defense Secretary Robert M. Gates, said they received a picture of mixed progress on the ground in Libya.

The headlong rebel retreat through the oil hubs of Ras Lanuf and Brega, en route to the strategic city of Ajdabiya, demonstrated the limits of their fighting ability against the superior firepower and military organization of Gaddafi loyalists. It also underscored how dependent the anti-Gaddafi forces have become on airstrikes and missile attacks by the Western-led coalition.

“Our volunteer forces in the front have only got light weapons and are facing a very large military might,” said a rebel spokesman, Col. Ahmad Bani. The largely untrained and poorly organized force lacks anti-tank and other heavy weapons.

Bani called on NATO forces to intervene more forcefully, although a U.S. military official said coalition airstrikes, including attacks by U.S. AC-130 gunships, had continued apace in combat areas along the Libyan coast, with 32 U.S. and 23 coalition airstrikes in the 12-hour period through midday in Libya.

Administration officials said U.S. participation in the strikes would subside rapidly once NATO formally takes overall command this week of all aspects of the operation.

Officials said they saw Libyan government gains during the day as temporary and part of the “fluid” back and forth of the ground combat. But they did not dispute the likelihood that the rebels will need more equipment and training to prevail, increasing the pressure to find out more about the opposition.

Several lawmakers briefed by Clinton, Gates and Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, said they were told that the United States is still trying to put together a full picture of the Libyan rebellion but believes that it does not contain large numbers of radical Islamic militants.

“Nobody had detected any significant presence, although they knew there were some people,” said Rep. Gary L. Ackerman (D-N.Y.). But “nobody’s vouching for resumes” at the moment, Ackerman said.

House Intelligence Committee Chairman Mike Rogers (R-Mich.), said he heard nothing in the briefing that turned him in favor of arming the rebels. Calling it a “horrible idea,” Rogers said: “We know what they’re against. We don’t really know what they’re for.”

A senior administration official said that “we know well” some of the more prominent members of the Transitional National Council, the group that has been the public face of the rebellion and that includes lawyers, intellectuals and former members of the Gaddafi government.

But “in terms of participants on the ground, that’s a deeper dive, obviously,” said the official, one of several interviewed who were not authorized to publicly discuss the administration’s efforts. “You have the leadership and the formal structure, and then the ground truth in various parts of the country where you have strong opposition” to Gaddafi, but little is known about who is leading those efforts.

British Foreign Secretary William Hague said Wednesday that his government has made no decision about arming the rebels and that “we want to know about any links with al-Qaeda.” But, he said, “given what we have seen” of the opposition political leaders, “I think it would be right to put the emphasis on the positive side.”

The CIA’s efforts represent a belated attempt to acquire basic information about rebel forces that had barely surfaced on the radar of U.S. spy agencies before the uprisings in North Africa.

Among the CIA’s tasks is to assess whether rebel leaders could be reliable partners if the administration opts to begin funneling in money or arms.

Obama took a key step in that direction by issuing a secret authorization known as a presidential “finding,” designed to pave the way for the flow of money or weapons. News of the finding, signed several weeks ago, was first reported Wednesday by Reuters.

Under law, the CIA requires special permission from the president to carry out activities designed to influence foreign events. A finding establishes a framework of legal authorities for specific covert activities, and in some cases for future actions that can be taken only after specific permission is given.

Such operations are fraught with risks. The CIA’s history is replete with efforts that backfired against U.S. interests in unexpected ways. In perhaps the most fateful example, the CIA’s backing of Islamic fighters in Afghanistan succeeded in driving out the Soviets in the 1980s, but it also presaged the emergence of militant groups, including al-Qaeda, that the United States is now struggling to contain.

Giving the CIA an expanded role in Libya would enable the administration to bridge the gap between the restrictions on coalition airstrikes and Obama’s stated goal of bringing Gaddafi’s four-decade rule to an end.

The CIA’s Special Activities Division includes paramilitary operatives who could help guide rebel operations as well as allied airstrikes.

Even amid an escalating campaign of coalition airstrikes, opposition forces have repeatedly mounted ill-advised assaults on Gaddafi positions and have been forced to retreat from territory they had gained.

If CIA paramilitary operatives were linked up with rebel leaders, “we’d be providing the intelligence on the location of the bad guys and saying, ‘Don’t you realize they’re just down the road here, and you’re going to get whacked if you go too far?’ ” said a U.S. official with access to intelligence on the fighting in Libya. “These guys don’t seem to be following any common-sense military advice.”

White House press secretary Jay Carney refused to comment on “intelligence matters” and reiterated Obama’s public statements that while no decision has been made about arming the rebels, “we’re not ruling it out or ruling it in.”

Officials emphasized that the U.S. military will have no role on the ground in assisting the rebels. “There is no planning for putting any U.S. boots on the ground” for any purpose, a U.S. military official said. “We have no mandate, no authority, no planning going on to that effect. . . . Nobody’s told us to be prepared to do that.”

Staff writers David Fahrenthold in Washington and Tara Bahrampour in Benghazi and correspondent Liz Sly in Tripoli contributed to this report.