US President Barack Obama has defended the first war launched under his presidency, insisting US military involvement in Libya will be limited.
Addressing Americans, he said US intervention had saved "countless lives" threatened by the forces of the "tyrant" 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.
'Regime change' ruled out
"Tonight, I can report that we have stopped Gaddafi's deadly advance," Mr Obama said, speaking from the National Defense University in Washington DC.
But the lead in enforcing the no-fly zone "and protecting civilians 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 taxpayers - will be reduced significantly," Mr Obama said.
http://www.bbc.co.uk/news/world-africa-12888826
Note: Update Record,29 March 2011 Last updated at 00:28 GMT