TRIPOLI, Libya - Libya's government pushed a cease-fire proposal Thursday and said for the first time that it was prepared to speak with its rebel adversaries, signaling that months of fighting and NATO bombardment may be closer to forcing some concessions.

Even so, the government insisted that Moammar Gadhafi would not relinquish power, which he has held for more than 40 years. His departure is a key demand of the United States, European leaders, and the rebels, who say they will not consider halting more than three months of fighting until Gadhafi goes.

Gadhafi "is in the heart of every Libyan. If he leaves, the entire Libyan people leave," said Prime Minister Al-Baghdadi al-Mahmoudi.

Mahmoudi said in Tripoli that he was willing to hold talks with "all Libyans," including members of the rebel administration based in the eastern city of Benghazi.

Officials from Gadhafi's regime said before that they would not speak to the rebel government, arguing that it did not represent Libyans.

Also Thursday, three rebel fighters were killed and 20 hurt in clashes with government forces near Misrata, said Dr. Mustafa Taha from the city's Hikma Hospital. It was unclear whether any government soldiers died in the clash near the western city, the only one under rebel control near Tripoli.

Late Thursday, at least five explosions were heard in Tripoli from NATO air strikes. The targets were not immediately identified. Libyan gunners aimed antiaircraft fire at the jets. Smoke was seen rising from the area of Gadhafi's compound, a frequent target of NATO air strikes.

In London, a person with knowledge of the situation said Britain had agreed in principle to supply Apache attack helicopters to the NATO effort. The person insisted on anonymity because no announcement had been made. France has agreed to supply attack helicopters, which could hit pinpoint targets more easily than planes but would also be vulnerable to ground fire.

Mahmoudi did not detail the government's latest cease-fire proposal, but he emphasized that NATO must be a party to it, not just the rebels. He would not say whether the government would meet NATO's demands to return its military forces to their barracks.

The White House dismissed the proposal as not credible. Such offers must be backed up by action, said U.S. deputy national security adviser Ben Rhodes. He said the Libyan government was not complying with the U.N. resolution that authorized the international military operation to protect the Libyan people from forces loyal to Gadhafi.

Mahmoudi sent a letter to European governments seeking their backing for the latest proposal.

Libya's rebel administration repeated its insistence that before any cease-fire could be considered, Gadhafi's regime must respond to demands in the U.N. resolution.

Besides a cease-fire, the resolution calls for an end to attacks on civilians, unimpeded access for humanitarian assistance, and talks on a solution that responds to Libyans' "legitimate demands."

In Deauville, France, escalating violence in Libya worried a gathering of rich world leaders as much or more than their own debts and joblessness, but they could not agree Thursday on how to punish Gadhafi or restore peace, highlighting the difficulty in making sure Arab uprisings have peaceful endings.

Russia says NATO has gone too far in its bombing campaign against Gadhafi's forces. In a possible bid to soften Russian resistance to the air strikes, leaders of the Group of Eight nations asked Moscow to act as a "mediator" with Libya, according to President Dmitry A. Medvedev's spokeswoman, Natalya Timakova. She did not elaborate on what kind of role that could be, in comments carried by Russian news agencies.