The US military is moving naval and air forces into position around Libya, the Pentagon said today, as Western countries weigh possible intervention against Moamer Kadhafi's regime.

"We have planners working various contingency plans, and I think it's safe to say as part of that we're repositioning forces to provide for that flexibility once decisions are made," Pentagon spokesman Colonel Dave Lapan told reporters.

The redeployment of "naval and air forces" would give US President Barack Obama a range of options in the crisis, said Lapan, without specifying what ships and aircraft had been given orders or what potential action was under consideration.

As Gaddafi's troops assaulted opposition forces, US and European leaders were weighing the use of NATO air power to impose a no-fly zone over Libya to stop Kadhafi from using air strikes against his own people.

For any military intervention, US commanders could turn to the USS Enterprise, which is currently in the Red Sea, as well as the amphibious ship the USS Kearsarge, which has a fleet of helicopters and about 2,000 Marines on board.

British Prime Minister David Cameron said this afternoon a possible no-fly zone over the Libya was being planned.

US Secretary of State Hillary Clinton said no naval action against Libya was planned.