U.S. Seeking U.N. Backing for Air Strikes on Libya

The United States, in a sharp shift in tone, wants the United Nations to authorize not just a no-fly zone to aid Libyan rebels but also air strikes against Libyan tanks and heavy artillery, U.S. officials said on Thursday.

The move toward a tougher stance in favor of military action comes after an extended internal debate within the Obama administration, and as the Libyan opposition appeals for immediate assistance to prevent the rebel capital of Benghazi from falling to forces loyal to Libyan leader Muammar Gaddafi.

The United States has concluded a "no-fly" zone should be adopted and other measures that go well beyond a no-fly zone, should be taken, including air strikes against Libyan tanks and heavy artillery, U.S. officials said.

The United States is also seeking U.N. authorization for other steps under consideration, including diverting frozen Gaddafi assets to Libyan rebels for buying weapons and tightening a Libyan arms embargo.

State Department Undersecretary of State William Burns said the United States supports international measures "short of boots on the ground" to address the Libyan crisis.He said Washington is concerned Gaddafi could "return to terrorism and violent extremism" and create turmoil in the Middle East.

Any military plan adopted must have active participation by Arab League nations.

"They have to do more than just support it," a senior official said.

Pentagon officials have made clear their wariness of instituting a no-fly zone with U.S. forces already engaged in Iraq and Afghanistan and a massive relief operation under way in Japan.

Obama has been under pressure from Britain and France to join together in taking tough action against Gaddafi before the moment to do so slips away.

The U.S. ambassador to the United Nations, Susan Rice, said on Twitter that urgent negotiations were continuing at the U.N. Security Council about a Libya resolution.

"US view -- need to take steps beyond no-fly zone to protect civilians," she wrote.

The former Libyan ambassador to the United States, Ali Aujali, who backs the rebels, appealed for immediate help in a CNN interview.

"President Obama, please, I am asking you for the second or third time, you know Gaddafi, you know what he will do," he said.