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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.
Gadhafi has declared a cease-fire, the official said, and the coalition is watching carefully to see if that declaration "is a pledge or just words."
An opposition spokesman said Monday there is no cease-fire, at least not in Misrata, a key city about two hours east of Tripoli.
The spokesman, Mohamed -- who would not divulge his last name out of concern for his safety -- said the destruction there is "unimaginable" and that Misrata was bombarded heavily over the past four days by forces loyal to Gadhafi.
"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, Mohamed 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 it 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 military operations began over the weekend, he said. In addition, air attacks have stopped Libyan ground forces from approaching the eastern rebel stronghold of Benghazi, and some are even turning back from the city, he said.
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.
Approximately 80 sorties were flown Monday, more than half of them by air forces representing countries other than the United States, he said.
Air forces from France, Spain, Italy, Denmark and Britain flew missions to maintain a no-fly zone over 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 coalition is also deciding who should be in charge of its military operations, Ham said.
NATO could command the mission, 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 because of the sensitivity of negotiations.
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.
Gadhafi's compound in Tripoli lay in shambles Monday after an attack by the United States and its allies.
Ham said the compound contains a command-and-control facility, which he said coalition forces attacked.
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."
Ham continued, "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 protecting innocent civilians.
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 Gadhafi out.
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 the opposition has compiled a list of names of Gadhafi loyalists and imprisoned 150 of them in Benghazi for them eventually to stand trial. Some of them, he said, had carried out attacks against their fellow Benghazi residents or were planning to.
Libya's request for an emergency Security Council meeting about the matter was not approved Monday.
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, and India, China, and Venezuela have also spoken out against the airstrikes.
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.
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.
Yussuf bin Alawi bin Abdullah, Oman's foreign minister, has said Arab League members agreed to support the no-fly zone despite reservations about military intervention.
The Libyan government has said that 48 people, mostly women, children and clerics, have died in allied attacks. U.S. Vice Admiral Bill Gortney, however, said there is no indication of any civilian casualties.
France -- which conducted the first strike in Libya on Saturday when fighter jets fired at a military vehicle -- also disputed claims of civilian deaths.
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