Tripoli:
Libyan government spokesman Moussa Ibrahim on Friday dismissed a ceasefire offer made by the rebels saying it was a "trick" and accused western leaders of "crimes against humanity".
The rebels said from Benghazi, their de facto capital, that they will agree to a cease-fire if Libyan Leader Moammar Gaddafipulls his military forces out of cities and allows peaceful protests against his regime.
But Moussa, speaking to a news conference in Tripoli, said that the rebels were making "impossible demands".
"So, okay, I could come to the rebels and say: 'rebels, I offer peace, get out of Benghazi on a ship, this is my condition.' You can't do that," he said.
The government spokesman said that if the rebels wanted peace, they would have accepted the government's earlier offer, before the no-fly zone resolution.
Moussa also slammed western leaders for the international airstrikes against Gadhafi's forces which began March 19.
"What this mad, criminal, immoral prime ministers and presidents of Europe are doing, is a crime against humanity."
"If they have any conscience, they should wake up to their crimes and stand down immediately, as prime ministers and presidents of Europe," Moussa said.
The head of the opposition's interim government Mustafa Abdul-Jalil made the ceasefire offering on Friday, after talks with United Nations envoy Abdelilah Al Khatib.
Al-Khatib also met Libyan government officials in Tripoli on Thursday before holding talks with rebels in hopes of reaching a political solution.
The UN resolution that authorised international airstrikes against Libya called for Gaddafiand the rebels to end hostilities.
Abdul-Jalil said the rebels' condition for a cease-fire is "that the Gaddafibrigades and forces withdraw from inside and outside Libyan cities to give freedom to the Libyan people to choose and the world will see that they will choose freedom."
"If you want peace, you keep things as they are, you sit down and you negotiate. But to make impossible demands is a trick. So what they are doing is not a genuine wish for peace," said Moussa on Friday.
A key Libyan official involved in negotiations on the future of Gadhafi's regime said Friday that Tripoli was attempting to hold talks with the US, Britain and France to find a mutual end to the crisis.
Abdul-Ati al-Obeidi, a former Libyan prime minister, said Gadhafi's government was reaching out to those leading the international military campaign in an attempt to halt the airstrikes.
The claim follows confirmation that a Libyan government aide has held talks in Britain with UK officials in recent days.
There were signs that the rebels were adopting more disciplined military tactics, spreading out across the desert in an attempt to flank Gadhafi's forces.
It was too early to say if the improvements will tip the fight in the rebels' favour.
They have been struggling to exploit the opportunity opened by international airstrikes hammering Gadhafi's forces since March 19.
Meanwhile, US defence officials on Friday announced that the Pentagon will soon stop firing Tomahawk cruise missiles against Libya, in addition to pulling its attack planes out of the international air campaign.
Defence Secretary Robert Gates and Navy Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, on Thursday announced in congressional testimony the decision to withdraw US combat aircraft from the NATO-commanded mission as of this coming Sunday.