Libya's government announced a "immediate" cease-fire on Friday, but witnesses in the besieged coastal city of Misrata told CNN a fierce pro-government assault is persisting and casualties are mounting.

"What cease-fire," asked a doctor in Misrata, who described hours of military poundings, descriptions of casualties, and dwindling resources to treat the wounded. "We're under the bombs."

"This morning they are burning the city," the doctor said. "There are deaths everywhere."

"Misrata is on fire," according to an opposition member -- who said tanks and vehicles with heavy artillery shot their way into the city last night and the assault continued on Friday. "Please help us."

CNN couldn't independently confirm these accounts and it is impossible to tell whether the fighters got word of the government cease-fire declaration. The move, which came hours after the U.N. Security Council authorizing the use of force to protect besieged civilians, drew quick skepticism from France and the United States.

In remarks televised across the globe, Libya's Foreign Minister Moussa Koussa told reporters in Tripoli the country decided on "an immediate cease-fire and the stoppage of all military operations." He noted that the country, since it is a member of the United Nations, is "obliged to accept the Security Council resolution that permits the use of force to protect the civilian population."

It was not immediately clear how these latest developments will affect plans of some countries to intervene militarily in Libya -- authorities in Britain and France had talked before Koussa's remarks of imminent military action.

But Koussa said Libya plans to protect civilians and provide them with humanitarian assistance and that it is obliged to protect all foreigners and their assets. He also called for a fact-finding mission to sort out the events on the ground.

Koussa says the Libya was disappointed in the imposition of a no-fly zone, arguing that it will hurt the civilian population. He also said the use of military power violates the country's sovereignty and goes against the U.N. charter, but he acknowledged that some countries may yet intervene.

"There are signs this indeed might take place," Koussa said.

But Bernard Valero, a French Foreign Ministry spokesman, said announcement "does not change the threat on the ground."

"Gadhafi is privy to folkloric declarations and we must remain extremely vigilant with regards to these declarations," he said.

Susan Rice, the U.S. ambassador to the United Nations, Libya has to be judged by its actions and not its statements.

Earlier Friday, talk emerged in Europe of swift military action against Gadhafi's regime.

Speaking in an interview with RTL radio, French government spokesman Francois Baroin said France plans to participate in what he described as "swift" efforts.

British Prime Minister David Cameron said Britain has started preparations to deploy aircraft, and "in the coming hours" they will move to air bases where they will be positioned for any "necessary action."

Spain will offer NATO the use of two military bases and also provide air and naval forces for use in operations involving Libya, Defense Minister Carme Chacon said on Friday in Madrid, a defense ministry spokesman told CNN.

The two bases to be offered in southern Spain are the Rota air-naval station, where a contingent of U.S. troops is also based, and the airbase at Moron de la Frontera. Those, as well as the offer to provide air and naval assets, would be subject to parliamentary approval, the minister said at an event at a Spanish air base in Madrid, the spokesman said.

U.S. President Barack Obama plans to make remarks on the Libyan crisis on Friday afternoon.

Asked whether the cease-fire declaration complicates a U.N.-sanctioned intervention, Michael Rubin, a Middle East expert at the American Enterprise Institute, said, "it is going to make it tougher without a doubt."

"One should credit Obama for getting the international community behind him, but it came at the price of momentum. The Libyans understand European weakness and know how to play off of it," Rubin said.

The council Thursday night voted 10 to 0 with five abstentions to authorize "states to take all necessary measures to protect civilians." It also imposed a no-fly zone, banning all flights in Libyan airspace, with exceptions that involve humanitarian aid and evacuation of foreign nationals.

The decisive Security Council move comes after weeks of civil war between the Gadhafi regime and opposition forces, a conflict spurred by an anti-government uprising and regime violence against civilians, which the U.N. resolution cites as "outrageous."

Details has not fully emerged of how an international military operation might unfold in Libya.

The United States and its NATO partners have several contingencies in place to act quickly, according to an administration official familiar with planning. They include air strikes and cruise missile attacks designed to cripple Libyan air defenses and punish the military units that are leading Gadhafi's push on opposition strongholds in the east, the official said.

Obama will insist on a major Arab role in any no-fly zone, the official said.

The Arab League's U.N. ambassador, Yahya Mahmassani, said two Arab countries would take part in a no-fly zone operation, but he was not sure which two.

U.S. Air Force Chief of Staff Gen. Norton Schwartz told a Senate Armed Services Committee hearing on Thursday that establishing a zone would take "upwards of a week."

But the U.S. military does not view a no-fly zone alone as sufficient to stop Gadhafi. Military officials have said that this move would not halt the heavy artillery the regime is using on the ground.

All commercial air traffic has been shut down in Libya, an official at Eurocontrol said on Friday.

The opposition, with devoted but largely untrained and under-equipped units, has suffered military setbacks this week. But their hopes were buoyed by the U.N. vote, particularly in rebel-held Benghazi, where an assault by pro-Gadhafi forces has been expected.

The resolution singles out the city. It says U.N. member states can "take all necessary measures ... to protect civilians and civilian populated areas under threat of attack in the Libyan Arab Jamahiriya, including Benghazi, while excluding a foreign occupation force."

Gadhafi's son Saadi told CNN Thursday evening that troops will change their tactics and take up positions around Benghazi Saturday or Sunday and assist people fleeing from the city.

The younger Gadhafi said there will be no large-scale assault. Instead police and anti-terrorism units will be sent into the rebel stronghold to disarm the opposition. Unspecified humanitarian groups can help with the exodus of civilians from Benghazi, Saadi Gadhafi said.

In a radio address aired on Libyan state TV, Gadhafi criticized residents of Benghazi and called them "traitors" for seeking help from outsiders.

Along with France, Britain and the United States voted for the resolution, which condemns the "gross and systematic violation of human rights, including arbitrary detentions, enforced disappearances, torture and summary executions."

It details enforcement of an arms embargo against Libya, the freezing of assets and a ban on most flights.

"The United States stands with the Libyan people in support of their universal rights," said Rice.

The abstentions came from China, Russia, Germany, India, and Brazil. Germany said it was concerned about a protracted military conflict. China said it opposes the use of armed force in international relations.

Latest Interviews

Raspy Rawls Interview Pt. 2

Raspy Rawls Interview Pt. 1

Latest VLogs

iLoveMakonnen "Loudest of the Loud Tour - On the Road Pt. 2"

Life With Ty Dolla $ign (Ep. 7)

Lil Durk's "Wherever I Go" Tour (Pt. 1)