By Missy Ryan and Susan Cornwell
WASHINGTON (Reuters) - Intelligence on the rebel forces battling Libyan leader Muammar Gaddafi has shown "flickers" of al Qaeda or Hezbollah presence but there is still no detailed picture of the emerging opposition, NATO's top operations commander said on Tuesday.
"We are examining very closely the content, composition, the personalities, who are the leaders of these opposition forces," Admiral James Stavridis, NATO's supreme allied commander for Europe and also commander of U.S. European Command, said during testimony at the U.S. Senate.
Gaddafi's troops on Tuesday reversed the westward charge of rebel forces as world powers met in London more than a week after the United States and other nations launched a military campaign aimed at protecting Libyan civilians.
While Stavridis said the opposition's leadership appeared to be "responsible men and women" fighting Gaddafi, he said that "we have seen flickers in the intelligence of potential al Qaeda, Hezbollah. We've seen different things."
"But at this point I don't have detail sufficient to say there is a significant al Qaeda presence or any other terrorist presence," he said.
The Pentagon says it is not communicating officially with the Libyan rebels.
Stavridis' comments came a day after President Barack Obama made his case for action in Libya in a televised address to Americans, who are wary of another war with U.S. troops already in Afghanistan and Iraq.
While Obama has said Gaddafi should leave power, he stressed the military mission endorsed by the United Nations was limited to protecting civilians and enforcing a no-fly zone over Libya.
'MORE CLARITY' NEEDED FOR EXIT PLAN
Even as the rebels struggle against Gaddafi's better-armed, better-organized troops, Stavridis said the long-time Libyan leader was likely to go if the coalition brought a range of military power to bear against him.
"If we work all the elements of power, we have a more than reasonable chance of Gaddafi leaving, because the entire international community is arrayed against him," he said.
Senators' questions about the make-up of the Libyan opposition reflects skepticism in Congress about the Obama administration's preparedness for a campaign that came together quickly after weeks of speculation about whether the United States would intervene.
It also underscores worries about who might take over in Libya if Gaddafi does go.
"It's premature to say what is our exit strategy until we have a little more clarity moving forward," Stavridis said.
The Libya campaign has also intensified fears in Congress about the high cost of military activities overseas.
The war in Afghanistan, for example, costs the United States around $9 billion a month. Stavridis said the Libya mission had cost "hundreds of millions of dollars" so far.
(Writing by Missy Ryan; Editing by John O'Callaghan and Deborah Charles)