Washington (CNN) -- All 28 NATO allies have authorized military authorities to develop a plan for NATO to take on the broader mission of civilian protection under U.N. Resolution 1973, Secretary of State Hillary Clinton said Thursday.
Clinton said she will travel to London to attend an international meeting on Libya on Tuesday.
She made her comments to reporters shortly after Secretary-General Anders Fogh Rasmussen told CNN that NATO had agreed to take command of enforcing the no-fly zone over Libya and was considering taking control of the full U.N.-backed military mission.
Rasmussen's announcement fell short of what U.S. President Barack Obama has sought, and it was unclear if concerns by Turkey and some other NATO allies over coalition airstrikes on Libyan ground forces would prevent NATO from agreeing to expand its command over the entire mission.
"What we have decided today is that NATO will enforce the no-fly zone," Rasmussen told CNN's Wolf Blitzer. "We are considering whether NATO should take on overall responsibility. That decision has not been made yet."
Rasmussen said he expected NATO to decide on the issue "within the coming days."
Asked if the announcement revealed a split in NATO over the mission, Rasmussen said no.
However, he also acknowledged that, if unaltered, the agreement would mean the overall Libyan mission would have two parts, with NATO enforcing the no-fly zone and the U.S.-led coalition that launched the mission handling a naval blockade and airstrikes.
The U.N. Security Council resolution authorizing the mission includes a section that allows coalition forces to take other steps as necessary to protect Libyan civilians. So far, the U.S.-led coalition has interpreted that to include airstrikes on Libyan ground forces threatening the rebel stronghold of Benghazi and in other areas.
NATO sources said Turkey was uncomfortable with such a role and raised concerns about that at Thursday's meeting.
Thursday's deal was reached after a conference call between Clinton and her counterparts from Britain, France and Turkey, according to diplomatic officials who spoke on condition of not being identified by name.
At NATO headquarters, Thursday's meeting extended long past its expected conclusion. NATO sources said a major sticking point involved the rules of engagement for coalition forces that will take over command of enforcing a no-fly zone and naval blockade of Libya.
When Rasmussen finally emerged to announce the agreement, it was clear that questions over the rules of engagement remained unresolved.
He said NATO would use the already established chain of command for enforcing the no-fly zone.
The NATO supreme commander, an American, would be in charge, but the mission would be under NATO control, Rasmussen noted. In addition, non-NATO partners, including Arab countries, would participate, Rasmussen said.
NATO sources told CNN that the shift in command for enforcing a no-fly zone was expected by Sunday night.
According to the sources, NATO has sent a directive to NATO's military chain of command asking for a plan on how to execute an expanded role for enforcement of U.N. Resolution 1973. Under the expanded role, called "no-fly plus" by some officials, NATO might be given more robust rules of engagement to ensure that civilians are protected, the sources said.
One proposal for "no-fly plus" would allow some coalition forces to withdraw from certain missions, the sources said.
So far, U.S. forces have taken on the bulk of the Libyan mission, according to figures provided by the Pentagon. Of the 175 Tomahawk missiles fired, 168 were from the United States and seven from Great Britain, the only two countries to possess them, while U.S. planes have flown almost two-thirds of the sorties and U.S. ships comprise more than two-thirds of the total involved.
The coalition got a new member Thursday, with the United Arab Emirates expressing support for the resolution on Libya and committing six F-16 and six Mirage aircraft to participate in patrols, according to the UAE minister of foreign affairs, Sheikh Abydulla bin Zayed Al Nahyan.
Obama has repeatedly said that the United States will turn over control of the Libya mission to allies within "days, not weeks."
The flurry of activity came even as the battle for control of Libya was continuing. After a fifth consecutive night of pounding by coalition jets, Libyans gathered at a seaside cemetery in Tripoli on Thursday for the funerals of 33 people Moammar Gadhafi's government said were victims of an airstrike.
State television said the dead were victims of the "crusader colonial aggression." Earlier, a Libyan government official said coalition planes struck the suburb of Tajura and state TV showed images of fires, smoldering vehicles and the charred bodies of the dead.
CNN could not independently verify the circumstances of the deaths or who the victims were. In Tripoli, CNN reporters go on government-organized tours in an effort to do their own reporting; independent movement for foreign journalists in Tripoli is very difficult and forbidden by the Libyan authorities.
At the cemetery, anger trumped grief and Gadhafi's message was loud and clear: innocent people were wrongly killed and the Libyan people will fight back.
Coalition leaders have reported no civilian casualties and said that Western jets have dropped precision bombs on military targets.
The reports of civilian deaths were given little credence by coalition forces, which launched airstrikes Thursday near Tripoli, Misrata and Ajdabiya in Libya.
"The only civilian casualties we know are for certain are the ones that the Libyan government itself has caused," U.S. Navy Vice Adm. Bill Gortney said.
More than 350 aircraft are participating in coalition efforts in enforcing a no-fly zone and protecting populations in Libya, with slightly more than half of the aircraft from the United States, he said. Nine other nations, including Qatar, are involved in the coalition, he said.
"When and where regime forces threaten the lives of their own citizens, they will be attacked," Gortney said. He urged Libyan forces to cease fighting.
Asked whether any Libyan forces loyal to Gadhafi have quit fighting, he said, "I'm not aware of any at this particular point in time.
He said coalition forces were not communicating with opposition forces on the ground.
At the United Nations, Secretary-General Ban Ki-moon said he sees no signs of a cease-fire by Libyan government authorities.
Ban told council members, "to the contrary, fierce battles continue in and around the cities of" Ajdabiya, Misrata and Zinan. Ban gave his briefing, as required by U.N. Resolution 1973, seven days after that resolution was passed by 10 votes and five abstentions. He added that his envoy to Libya told Libyan authorities that if the government did not comply with the cease-fire resolution, "the Security Council was prepared to take additional measures."
He said he was sending his special envoy to an African Union meeting to be held Friday in Addis Ababa, Ethiopia, at which representatives of the Gadhafi government and the opposition were expected to attend. "Their aim: to reach a cease-fire and political solution."
But there was no sign that any such solution was near. So far, the aerial war has been unable to stop Gadhafi's armor, and the battle for two cities -- Misrata in the west and Ajdabiya in the east -- raged on Thursday.
A Misrata resident told CNN that he heard an explosion and that snipers loyal to Gadhafi were shooting from rooftops in the besieged city. They killed six people near the central hospital, a doctor told CNN.
The doctor said 109 people have been killed in the past week of fighting and more than 1,300 have been wounded since anti-Gadhafi protests erupted last month.
Witnesses in Misrata are not being identified by CNN for security reasons. Journalists have no access to the city and cannot independently confirm reports of violence.
The battle for Misrata, Libya's third-largest city, has been ongoing for more than a week.
British Foreign Secretary William Hague said Thursday that many residents remain trapped in their homes without electricity and communications and with a dwindling supply of food and water.
In the east, Gadhafi's tanks were shelling Ajdabiya, where fighting had occurred the day before. Loyalist forces still controlled the northern and western gates to the city.
"This underlines the appalling danger its inhabitants would be in without coalition action, as do continued threats by Gadhafi forces to 'massacre' residents in areas under bombardment," Hague said.
The coalition has established a no-fly zone that spans from east to west along Libya's coast. French jets fired air-to-ground missiles on a Libyan combat aircraft Thursday that was in violation of the no-fly mandate, destroying it, the French Defense Ministry said. The plane was struck as it was landing in a Misrata airfield.
Though the rebels may be in a better position now, a U.S. official said Gadhafi's forces still have the upper hand.
They remain capable of carrying out attacks on the opposition, are relatively well-organized and continue to fight effectively, the official said.
Aid agencies, restricted from accessing most parts of the country, expressed grave concern for Libyans living in battle zones.
"It's unclear how civilians are faring in the areas affected by hostilities," said Simon Brooks, head of the International Committee of the Red Cross mission in Libya.
"We're getting alarming reports from cities like Ajdabiya and Misrata, where the conflict has been raging for weeks now."
Officials said they hoped the transition to NATO control would be seamless. NATO already has ships in the Mediterranean Sea to enforce an arms embargo.
A key NATO ally, Turkey, voted Thursday to participate in the alliance's naval operations but only in support of the arms embargo against Libya. It will not conduct military strikes.
Critics are also calling for a clearer explanation of U.S. policy in the North African nation.
U.S. President Barack Obama, who just wrapped up a five-day trip to Latin America, has insisted that the goal of the U.N.-sanctioned military mission is strictly to prevent a humanitarian crisis.
Specifically, the U.N. mandate calls for protecting Libyan rebels and other civilians from attacks by forces loyal to the strongman.
U.S. officials have indicated they hope Gadhafi will be removed quickly by forces loyal to him, though they haven't publicly called for a coup.
The international airstrikes against Libyan military positions began over the weekend after Gadhafi defied a United Nations-mandated cease-fire to stop attacks against civilians.
The war was sparked in February by protests demanding an end to Gadhafi's nearly 42-year rule. The Libyan strongman responded with force against civilians, prompting the international community to take action.
France launched the air campaign, and Britain and the United States followed. Britain has announced an international meeting for next Tuesday to assess the situation in Libya.
CNN's Nic Robertson, Arwa Damon, Elise Labott, Paula Newton and Jim Bittermann contributed to this report.