France is pushing for NATO approval to extend military strikes on Muammar Gaddafi's army to strategic logistical targets, to try to break a deadlock in Libya's civil war as the civilian death toll mounts.
The push comes as France and Britain, which are leading the campaign in Libya, struggle to get coalition partners to step up participation or contribute more hardware, despite pleas from rebels that civilians are dying in the besieged city of Misrata.
The United States and European NATO allies rebuffed French and British calls on Thursday to contribute more actively to ground strikes in Libya, and military sources say neither Paris nor London plan to deploy any extra aircraft.
France used military helicopters to fire on armoured vehicles in its recent intervention in Ivory Coast, which sped up the ouster of former president Laurent Gbagbo.
But it has made no move to deploy them in Libya, where they would make easy targets for Gaddafi's army.
NATO forces have around 195 aircraft, including fighter jets and refuelling tankers, at their disposal for Libya operations, around half of which have been supplied by France and Britain.
Officials say seven of the 28 NATO countries -- Britain, France, Canada, Belgium, Denmark, Norway and the United States -- have been taking part in air strikes. Others are enforcing the no-fly zone without bombing or supporting it in other ways.
Douglas Barrie, a military aviation expert at London's International Institute for Security Studies, said attack helicopters and armed unmanned aircraft, or drones, could be of use in Libya.
UK Foreign Secretary William Hague said Britain was talking to other countries about providing more strike aircraft.
A member of the opposition transition council told Reuters on today that the West must ramp up its operations and consider arming the rebels or sending in troops to fight Gaddafi's forces.
In a strongly-worded, jointly-written article published in newspapers on both sides of the Atlantic, British Prime Minister David Cameron, French President Nicolas Sarkozy and US President Barack Obama said leaving Gaddafi in power would be an 'unconscionable betrayal' of the Libyan people.
'It is unthinkable that someone who has tried to massacre his own people can play a part in their future government,' the leaders wrote.
'So long as Gaddafi is in power, NATO and its coalition partners must maintain their operations so that civilians remain protected and the pressure on the regime builds,' they said.
