UNITED NATIONS -- The United Nations gave strong backing to Libya's former rebels Friday, handing their National Transitional Council the country's U.N. seat and then lifting and modifying some sanctions imposed on Moammar Gadhafi's regime.

The General Assembly's vote to accept the credentials of the National Transitional Council, which led the rebellion that ousted Gadhafi, gave its representative the right to speak at the United Nations. Libya's former deputy ambassador Ibrahim Dabbashi, who early on denounced Gadhafi and backed the rebels, addressed the Security Council hours later.

"Today is undoubtedly a decisive, historic day in the life of the Libyan people," Dabbashi said. "It is an indication that dictatorship has fallen, a period of terror, of denial of freedom and of violation of human rights has now come to an end for the Libyan people."

"The fact that the National Transitional Council today takes Libya's seat at these United Nations indicates that a new page has been opened in history of the Libyan people -- a page that has been marked by the blood of Libya's sons," he said.

Libyan fighters on Friday came under heavy fire from rockets, machine guns and snipers as they tried to push into two key Gadhafi strongholds in a concerted attempt to crush resistance by his loyalists.

In one of those areas, Bani Walid, the anti-Gadhafi forces had retreated by the end of the day.

Turkish Prime Minister Recep Tayyip Erdogan flew into Tripoli to meet the new government, stopping to join Friday prayers and address a small crowd in the city's central Martyrs' Square. He joined in calls for Gadhafi and his supporters to lay down their arms and warned the "oppressors" in Syria that they also would not survive.

Anti-Gadhafi forces had moved cautiously against the bastions of the former regime since taking Tripoli last month, keen to avoid civilian casualties and concerned about the resistance they might face. But on Friday, they appeared to have decided the time for waiting was over.

"It is a concentrated effort," said National Transitional Council spokesman Jalal el-Gallal. "The intensity will only increase."

Dabbashi spoke after the Security Council unanimously approved a resolution establishing a new U.N. mission in Libya in response to a request from the NTC for help in establishing the new government.

The resolution also unfreezes assets of two Libyan oil companies, lifts a ban on flights by Libyan aircraft and modifies an arms embargo to allow Libyan authorities now controlling the country to buy arms "intended solely for security or disarmament assistance."

Under the resolution, the no-fly zone imposed in March after Gadhafi launched his crackdown on regime opponents will remain in place but be kept under review.

The resolution lifts the asset freeze on the Libyan National Oil Corp. and Zueitina Oil Co. and modifies the asset freeze on the Central Bank of Libya, the Libyan Foreign Bank, the Libyan Investment Authority and the Libyan Africa Investment Portfolio.

The Security Council retained the asset freeze and travel ban against Gadhafi and key family members and regime supporters.