With NATO taking charge of the coalition effort on Thursday, US officials confirmed Friday that American fighters, ground-attack aircraft and cruise missiles would be pulled out of the operation starting this weekend.
The move follows pledges by President Barack Obama to quickly shift the lead to allies in the NATO-led coalition, with the US military playing a supporting role -- providing planes for mid-air refueling, jamming and surveillance.
"As we transition to a support role, our focus will be on providing enabling capabilities and not on strike capabilities," a US defense official, who spoke on condition of anonymity, told AFP.
Some lawmakers heavily criticized Obama over the decision at hearings on Thursday, saying NATO allies lacked ground-attack aircraft that were crucial against the Libyan regime's tanks and artillery.
In keeping with the handover, US sorties aimed at striking targets in Libya had also been scaled back in recent days.
American pilots flew only 10 out of 74 strike sorties in the past 24 hours up to 0800GMT Friday, the US defense official said.
US naval ships were also being gradually withdrawn from the seas off Libya and Tomahawk cruise missile attacks from American submarines had receded after an onslaught in the opening days of the operation.
No Tomahawk missiles had been launched in the past 24 hours, the official said.
Top US military officer Admiral Mike Mullen said the planes being withdrawn included the heavily-armed A-10 Thunderbolts and AC-130 gunships, both used to hit tanks and other ground targets.
Mullen said the combat aircraft would be on stand-by and could be ordered back to the mission if requested by the Canadian officer now leading the operation, Lieutenant General Charles Bouchard.
Some Republican lawmakers accused Obama of taking a half-hearted approach to the war, pulling out ground-attack aircraft just as opposition forces were on the retreat.
"Your timing is exquisite," Republican Senator John McCain told Mullen and Defense Secretary Robert Gates.
McCain, defeated by Obama in the 2008 presidential election, said that "withdrawing our unique offensive capabilities at this time sends the exact wrong signal both to our coalition partners as well as to the Kadhafi regime, especially to those Libyan officials whom we are trying to compel to break with Kadhafi."
Mullen said a US commander in the operation had assured him that allied aircraft were completely capable.
The commander "had a high level of confidence that they would be able to continue to execute this mission," Mullen said.
While the US military had provided the bulk of the firepower in the opening of the campaign launched March 19, the American commitment would "significantly ramp down" in coming days, Defense Secretary Robert Gates told lawmakers.
The US contribution from now on would be confined to electronic jamming, mid-air refueling, surveillance and search and rescue efforts, he said.
