* Washington takes Mali action 'very seriously'
* Panetta says action should be seen as 'international effort'
* U.S. still evaluating what assistance to give France
By David Alexander
ROME, Jan 16 (Reuters) - The United States takes the French fight with al Qaeda-affiliated militants in Mali "very seriously" but must evaluate French military needs and the legal basis for U.S. action before providing aid, Defense Secretary Leon Panetta said on Wednesday.
Panetta, speaking to reporters in Rome, said the United States already was providing information to Paris to help French forces in their effort to disrupt the advance of Islamist groups in Mali until the ECOWAS grouping of African nations can put troops on the ground.
"The administration takes this very seriously and they have indeed been reviewing areas where assistance can be provided," said Panetta, who is on a week-long trip to Europe that will likely be his last as defense secretary. "I'm confident that we're going to be able to provide that assistance."
Asked why a decision on the issue was taking so long, Panetta said the U.S. administration wanted to make sure of the kind of assistance Paris needed and "that we have the proper legal authorities to be able to provide that."
Asked if the legal authorities granted the administration to battle al Qaeda following the Sept. 11 attacks weren't enough, Panetta quipped: "One thing I've learned is every time I turn around I face a group of lawyers."
"The lawyers basically have to review these issues to make sure that they feel comfortable that we have the legal basis for what we're being requested to do," he added. "I'm not going to say these questions are insurmountable. ... I'm confident that we'll able to provide the assistance."
Paris has sent hundreds of soldiers to Mali and carried out air raids since Friday in the northern half of the country, which was seized last year by an Islamist alliance that included al Qaeda in the Islamic Maghreb.
WAITING FOR ECOWAS
The French action that began on Friday was to halt a move by the militants toward the Malian capital until an ECOWAS force could be deployed in the region.
Panetta told reporters on Monday the Pentagon was looking at providing France with logistics, intelligence and airlift capabilities.
Western and West African states fear the al Qaeda-linked insurgents will use Mali's north, a vast and inhospitable area of desert and rugged mountains the size of Texas, as a base for international attacks.
"From my own background in having dealt with al Qaeda, they are a threat," Panetta said. "Wherever they locate and try to establish a base for operations, I think that that constitutes a threat that all of us have to be concerned about."
Panetta said the concern was that the group could use Mali to carry out attacks like the one on Wednesday in Algeria, where Islamist militants attacked a gas field, reportedly killing three people and kidnapping up to 41, including seven Americans.
"That's the kind of thing terrorists do. And that's why we're concerned," he said.
Panetta said he had discussed Mali with Italian Defence Minister Giampaolo di Paola and other Italian leaders during visits on Wednesday. Italy and Germany have both announced plans to provide France with assistance, and Britain is providing transport aircraft.
"I don't think there's any question that all of us concur that we ought to provide whatever assistance we can to assist the French in their effort," he said, adding that French actions had been endorsed by the United Nations and should be considered an "international effort." (Reporting By David Alexander; Editing by Kevin Liffey)