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Tripoli, Libya (CNN) -- Libyan leader Moammar Gadhafi's momentum has stopped and rebels have been able to hold onto areas that government forces had been poised to capture just a few days ago, a U.S. official said Monday.
The regime's efforts appeared to have "stalled" as Gadhafi has declared a cease-fire, the official said.
The coalition is watching carefully to see if Gadhafi's assertion "is a pledge or just words," the official said.
An opposition spokesman said he already knew the answer, at least as it pertains to Misrata, a key city about two hours east of Tripoli. "There is no cease-fire in Misrata," said Mohamed, who would not divulge his last name out of concern for his safety. "The destruction is unimaginable."
He said the city, the last in the west under rebel control, has had no electricity, telephone service or drinking water for at least two weeks and was bombarded heavily over the past four days by forces loyal to Gadhafi.
Gallery: Civil war in Libya "He keeps talking about a cease-fire, but he hasn't observed that for one minute here," Mohamed said.
Based on what he saw at a hospital, the opposition spokesman said Monday's death toll among civilians at the hands of pro-Gadhafi forces was 15. Another 51 civilians died in weekend attacks by pro-Gadhafi forces, Mohamed said.
Late Monday, state television reported that Misrata was firmly in the hands of government forces, and urged residents to celebrate.
The head of U.S. forces in Libya told reporters that coalition forces had made "very effective" progress Monday toward their goal of enforcing a U.N. Security Council resolution intended to protect civilians from attack by forces loyal to Gadhafi.
"I assess that our actions to date are generally achieving the intended objectives," said Gen. Carter Ham, commander of U.S. Africa Command. "We think we have been very effective in degrading his ability to control his regime forces."
No Libyan aircraft has been observed operating since the onset of military operations over the weekend, he said. In addition, air attacks have stopped Libyan ground forces from approaching Benghazi, "and we are now seeing ground forces moving southward from Benghazi," he said.
Citing "a variety of reports," Ham said ground forces loyal to Gadhafi that had been near Benghazi "now possess little will or capability to resume offensive operations."
During the prior 24 hours, he said, U.S. and British forces launched 12 Tomahawk land attack missiles aimed at command-and-control facilities, a Scud surface-to-surface military facility and, in a repeat attack, an air defense site.
Air forces from France, Spain, Italy, Denmark and Britain flew missions to maintain a no-fly zone over the eastern rebel stronghold of Benghazi, Ham said.
Actions on Monday were focused on extending the no-fly zone to al-Brega, Misrata and then to Tripoli, a distance of about 1,000 kilometers (more than 600 miles).
Canadian and Belgian forces joined coalition forces Monday, he said, and aircraft carriers from Italy and France have added "significant capability" in the region.
The process of transitioning leadership of military operations to a designated headquarters was in development, Ham said. "This is a very complex task under the best of conditions," he said.
NATO could command the coalition's no-fly mission in Libya, but some Arab nations are hesitant to fly under a NATO banner, and that has held up the move, said one official who asked not to be identified due to the sensitivity of negotiations.
"NATO has the capability to do a rapid switchover," the official said. "The problem is, they have to do everything by consensus."
If Arab nations don't sign on to a NATO mission, the other option would be to create an ad hoc command-and-control structure piece by piece, the defense official said. But that would take time, the official said.
Ham said he knew little about the location of Gadhafi and has not tried to find him. Instead, he said, "we have expended considerable effort to degrade the Libyan regime's military command-and-control capability, and I think we've had some fairly significant effect in that regard."
On Monday, approximately 80 sorties were flown, more than half of them by air forces representing countries other than the United States, he said.
Gadhafi's compound in Tripoli lay in shambles Monday after an attack by the United States and its allies.
Ham said the compound measures some 500 meters (a third of a mile) by 1,000 meters (.6 of a mile) and contains a command-and-control facility. "That's the facility that was attacked," he said.
But Gadhafi himself has not been targeted and there are no plans to do so, Ham added. In fact, he said, "I could see accomplishing the military mission, which has been assigned to me, and the current leader would remain the current leader. Is that ideal? I don't think anyone would say that that is ideal. But I could envision that as a possible situation, at least for the current mission that I have."
U.S. President Barack Obama repeated Monday that Gadhafi "needs to go," but he acknowledged the strongman may remain in power for some time because the allied military mission in North Africa has a narrow mandate of just protecting innocent civilians.
"Our military action is in support of an international mandate from the Security Council that specifically focuses on the humanitarian threat posed by Colonel Gadhafi's people," Obama told reporters in Santiago, Chile.
But, he noted, "Now, I also have stated that it is U.S. policy that Gadhafi needs to go."
Obama said he's hopeful that other "tools" the administration has used, such as freezing billions in Libyan assets, will eventually help the Libyan people push out Gadhafi.
CNN's Nic Robertson was among several Western journalists taken inside Gadhafi's bombed compound in Tripoli by Libyan officials early Monday to survey the destruction. He reported a four-story building was heavily damaged.
Ham said the operations were being carried out "with very high concern for civilian casualties."
A press and information coordinator for rebels in Benghazi said rebel leaders do not want coalition forces to target Gadhafi. That, said Mohammed Fannoush, is the job of the opposition. He added that the opposition has compiled a list of names of Gadhafi loyalists and has imprisoned 150 of them in Benghazi to eventually stand trial. Some of them, he said, had carried out attacks against their fellow Benghazis or were planning to carry out such attacks.
Meanwhile, the U.S. military mission in Libya may have peaked, Africa Command spokesman Vince Crawley said Monday.
"We are moving from the action phase to a patrolling phase," he said. "Our aircraft participation has ... plateaued, if not reduced somewhat."
Libya's request for an emergency Security Council meeting about the matter was not approved Monday, and a diplomat said the Security Council is likely to continue discussions Thursday at a planned briefing on Libya.
The Security Council resolution, which passed Thursday, allows member states "to take all necessary measures to protect civilians under threat of attack in the country ... while excluding a foreign occupation force of any form on any part of Libyan territory."
Support for the attacks was not universal. The Russian government said the mission has killed innocent civilians and urged more caution. The Foreign Ministry in Moscow cited reports that "nonmilitary" targets were being bombed, including a cardiac center. India, China and Venezuela have also spoken out against the airstrikes.
Arab League Secretary-General Amre Moussa told CNN Monday that the league's vote on March 12 to support a no-fly zone does not mean that all Arab countries will participate. "The resolution by the Arab League addressed ... the issue of a no-fly zone and the request by the U.N. Security Council to establish this zone," he said. "But beyond that, the participation is a matter of sovereign decision by any member state."
Yussuf bin Alawi bin Abdullah, Oman's foreign minister who joined Moussa to answer questions when the Arab League passed the resolution, said then that Arab League members agreed to support the no-fly zone despite reservations about military intervention.
But, he added, "Be assured the Arab countries will not accept the intervention of the NATO coalition."
Sen. John Kerry, D-Massachusetts, interpreted the league's resolution as perhaps more robust than that laid out Monday by Moussa. "We wouldn't be there if this hadn't been asked for by the Gulf states who saw their brothers and sisters being killed by Gadhafi," he said.
"We wouldn't be there if the Arab league had not passed its own statement asking us to put a no-fly zone in place. We are there precisely because the Arab world has asked us to try to help save Muslim lives from mercenary forces that Colonel Gadhafi hires to kill his own people."
Kerry said the pressing nature of the operation meant the coalition "had to be put into effect very, very quickly." Too quickly, he said, to integrate military forces from Arab countries that do not conduct flight exercises or joint operations with U.S./NATO forces.
Arab League chief of staff Hisham Youssef said Sunday that there had been no shift in the organization's support for the no-fly zone.
"The Arab League position has not changed. We fully support the implementation of a no-fly zone," Youssef said. "Our ultimate aim is to end the bloodshed and achieve the aspirations of the Libyan people."
U.N. Secretary-General Ban Ki-moon -- who met Saturday with Moussa and other world leaders to discuss Libya -- said support from Arab leaders was key to the Security Council's decision.
"The strong recommendation by the league of Arab states to take decisive measures -- including the establishment of a no-fly zone -- figured prominently in the adoption of the Security Council resolution," Ban told reporters in Egypt on Monday. "This decisive measure is meant to protect the civilian population, who are being killed by Colonel Gadhafi and his regime."
The Libyan government has said that 48 people, mostly women, children and clerics, have died in allied attacks.
However, U.S. Vice Admiral Bill Gortney said, "We have no indication of any civilian casualties."
And France -- which conducted the first strike in Libya on Saturday when fighter jets fired at a military vehicle -- also disputed claims of civilian deaths.
"There is no information of killed civilians recorded by the French command," French government spokesman Francois Baroin said Monday on the French TV channel Canal-plus. "We must be cautious of communication campaigns and propaganda."
Ahmed Gebreel, a member of the Libyan opposition, told CNN the Gadhafi government collected bodies of people killed in fighting in the past week and displayed them over the weekend in an attempt to show they were killed by coalition airstrikes.
Also on Monday, the New York Times announced that its four journalists who had been held in Libya since last week had been released.
CNN's Ivan Watson, Virginia Nicolaidis, Pam Benson, Arwa Damon, Yousif Basil, Charley Keyes, Chris Lawrence, Jill Dougherty, Elise Labott, Paula Newton, Richard Roth, Maxim Tkachenko, Niki Cook and journalist Mohamed Fadel Fahmy contributed to this report