US President Barack Obama has defended the first military intervention¹ of his presidency², insisting US involvement in Libya will be limited.

美国总统奥巴马为自己任期内进行的首次军事干预行动做辩护，他坚持美国对利比亚的干预是有限的。

He told Americans US participation³ in the coalition⁴ had saved "countless⁵ lives" threatened by the forces of the "tyrant⁶" Muammar Gaddafi.

But having led the initial campaign, the US would hand over to Nato allies on Wednesday, he said.

Meanwhile, the rebel advance inside Libya has been slowed down near Sirte.

While Nato insists it is impartial⁷ in the conflict, Russia has renewed its expressions of concern, saying intervention in an internal civil war is not sanctioned by UN Security Council Resolution 1973.

Some 40 delegations⁸ - from the coalition, the UN, Nato, the African Union and Arab League - are preparing to meet in London on Tuesday to discuss the way forward for Libya.

'Regime change' ruled out

"Tonight, I can report that we have stopped Gaddafi's deadly advance," Mr Obama said, speaking from the National Defense⁹ University in Washington DC.

But the lead in enforcing the no-fly zone "and protecting civilians¹⁰ on the ground" would now move to US "allies and partners".

"Because of this transition to a broader, Nato-based coalition, the risk and cost of this operation - to our military, and to American taxpayers¹¹ - will be reduced significantly," Mr Obama said.

"We must always measure our interests against the need for action," the president continued.

"But that cannot be an argument for never acting¹² on behalf of what's right...

"We were faced with the prospect¹³ of violence on a horrific scale. We had a unique ability to stop that violence: an international mandate¹⁴（授权，命令） for action, a broad coalition prepared to join us, the support of Arab countries and a plea for help from the Libyan people themselves."

He said that to broaden the aims of the military mission in Libya to overthrowing¹⁵ Col Gaddafi would be a mistake. The US, he said, had gone down that road in Iraq and could not afford the cost in lives, time and money again.

Earlier on Monday, Mr Obama spoke¹⁶ by video conference with French President Nicolas Sarkozy, German Chancellor¹⁷ Angela Merkel and UK Prime Minister David Cameron as part of his regular consultations¹⁸ with European allies.

The leaders agreed that Col Gaddafi "had lost any legitimacy¹⁹ to rule and should leave power, and that the Libyan people should have the political space to determine their own future", a White House statement said.