Nato chief asks for more fighter jets in Libya

He cited a briefing given to Nato ministers by the alliance's top commander James Stavridis, who noted that Gaddafi forces are changing tactics and hiding heavy arms in populated areas, which makes it more difficult for allied forces to target and destroy them.

Rasmussen admitted that while ministers agreed in general to continue their support for mission Unified Protector, he did not get "specific pledges or promises" for more fighter jets. "But I heard indications that give me hope. And by nature I'm an optimist," he added.

France and Britain have in recent days called on their Nato allies to step up their contributions to the mission, as Gaddafi forces continue to strike the city of Misrata, where hundreds of civilians are feared to have been killed in the six-week long siege.

"A massacre ... will take place here if Nato does not intervene strongly," a rebel spokesman in Misrata told Reuters on Thursday.

When the US handed over to Nato the control of the Libyan operations two weeks ago, it also pulled back some 50 fighter jets, hoping that other Nato countries would step up their contributions. Britain, France, Denmark, Belgium and Norway are now left to do most of the airstrikes.

French foreign minister Alain Juppe said he made a personal appeal to his US counterpart Hillary Clinton for Washington to resume air raids in Libya, but his calls were rebuffed.

"I told her we needed them back, we would have liked them to return," he said, adding that Clinton reassured him US planes would continue to fly on a case-by-case basis.

In separate remarks to press, Clinton slammed the "atrocities" in Misrata, but was not willing to pledge any more fighter jets than Washington has already committed to the mission. She also called on the alliance to maintain "resolve and unity," as some member countries - notably the host of the ministerial meeting, Germany - are openly against the Nato-led strikes.

The so-called Brics emerging powers - Brazil, Russia, India, China and South Africa – also criticised the Nato mission after talks in China and urged an end to the two-month civil war.

Meanwhile, Colonel Gaddafi on Thursday made his appearance on the streets of Tripoli, driving in an open car and shaking his fists in the air, despite all the calls from the international community for him to step down.

"God, Libya, Moammar and no one else," supporters shouted around him.

A joint article published by the leaders of Britain, France and the US said that a future with Gaddafi still in power would be an "unconscious betrayal" by the rest of the world.

"It is unthinkable that someone who has tried to massacre his own people can play a part in their future government," Sarkozy, Cameron and Obama wrote.