PARIS - World leaders met Saturday in a summit in Paris that could be the final step before international military action against Moammar Gadhafi's forces in Libya.

France's President Nicolas Sarkozy greets US Secretary of State Hillary Clinton (L) at the Elysee Palace ahead of wider international talks on Libya in Paris March 19, 2011.  [Photo/Agencies]

The emergency summit of Arab and European, hosted by French President Nicolas Sarkozy took place as Gadhafi's forces swarmed into the one-time rebel stronghold of Benghazi - apparently ignoring a proclaimed cease-fire by Libya's regime.

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The meeting of 22 leaders, including British Prime Minister David Cameron and US Secretary of State Hillary Clinton, took full shape only shortly before it was to begin: The African Union was not attending, as had previously been expected, but the Iraqi foreign minister was among those announced as late participants.

French officials have said that they expect military action could begin within hours after the meeting - but the outcome remained uncertain and it was not clear what effect developments on the ground might have.

France, Britain and the United States were among the major backers of a muscular UN Security Council resolution passed Thursday that authorizes a no-fly zone over Libya and "all necessary measures" to protect civilians.

France's UN ambassador Gerard Araud told BBC Newsnight that he expected military action to begin within hours of the hastily organized summit in response to the onslaught by Gadhafi's artillery, warplanes and tanks against rebel-controlled areas.

The African Union - which counts Libya as a member - was meeting in Nouakchott, Mauritania, and was looking to take on a "mediation" role in the crisis, said a French diplomatic official on condition of anonymity because he was not authorized to speak publicly about the matter.

Arab League Secretary-General Amr Moussa and UN Secretary-General Ban Ki-Moon were on hand among the 22 world leaders in Paris - many European - along with Qatar's emir Sheikh Hamad Bin Khalifa Al Thani and foreign ministers of Jordan, Moroccan and the United Arab Emirates.

Sarkozy, Clinton and Cameron were also scheduled to hold trilateral talks after the summit.

NATO's North Atlantic Council was expected to issue an order to launch the operation in coming days. Officials said the military staff was putting the final touches on plans to deploy fighter bombers, tankers, helicopters and surveillance planes to several air bases along Europe's southern rim.

NATO consultations that began Friday were adjourned to await the results of the summit in Paris.

Six Danish F-16 fighter jets landed at the US naval air station in Sigonella, Sicily, on Saturday. Danish air force spokesman Lars Skjoldan said they would be ready for operation in Libya by Sunday.

Italy has offered the use of seven air and navy bases already housing US, NATO and Italian forces. Sigonella's size and close proximity to Libya makes it a key staging point.

Moammar Gadhafi's government declared a cease-fire Friday in an attempt to outmaneuver Western military intervention, but witnesses said shells were raining down well after the announcement. Early Saturday, a plane was shot down over the rebel stronghold of Benghazi.

On Friday, Britain and France took the lead in plans to enforce a no-fly zone over Libya. Paris said it was ready for possible military action, without specifying, while Britain ordered warplanes to the Mediterranean.

"The clock is ticking and we must be ready to act quickly," Cameron said Friday, adding that Gadhafi must prove he was serious about a cease-fire to avoid military strikes.

In a joint statement to Gadhafi late Friday, the United States, Britain and France - backed by unspecified Arab countries - said a cease-fire must begin "immediately" in Libya, the French presidential palace said.

The statement called on Gadhafi to end his troops' advance toward Benghazi, and pull them out of Misrata, Adjadbiya and Zawiya, and called for the restoration of water, electricity and gas services in all areas. It said Libya's population must be able to receive humanitarian aid.

The United States has a host of forces and ships in the area, including submarines, destroyers, amphibious assault and landing ships. US officials have not specified the possible American role - although Obama said Friday that no US ground troops would be involved.

NATO surveillance AWACS planes flying off the Libyan coast are already providing 24-hour coverage of the situation in the air and on the battlefields. Analysts said no-fly zone aircraft would be flying from NATO bases such as in Sigonella, Sicily, Aviano in northern Italy, Istres in southern France, and Ventiseri-Solenzara in Corsica.