"That's how the international community should work, more nations (with) the United States right there at the centre of it, but not alone, everybody stepping up, bearing their responsibilities," Obama said.

"That's what it means to be (the) United Nations," Obama said, opening the new facility named after Ron Brown, former president Bill Clinton's commerce secretary, who perished in a plane crash in Croatia in 1996.

"We believe that the world is more secure and the interests of the United States are best advanced when we act collectively," said Obama.

"The burden of action should not always be America's alone." The current air operation over Libya has seen the United States play the dominant role, but Washington says it will increasingly play a support role to its partners including France, Britain, Italy, and Arab states including Qatar. NATO earlier delayed its assumption of command and control responsibilities for the operation by one day to Thursday, to allow a smoother handover from the United States.

"Today in Libya, we are showing what's possible when we find our courage; when we fulfil our responsibilities and when we come together, as an international community, to defend our common interests and our common values," Obama said.

"We're saving innocent lives."