France says military action against Libya could begin within hours of a special international summit in Paris today.
US Secretary of State Hillary Clinton will join the British and French leaders, and others from Arab countries.
The US says Libya has already violated the UN resolution imposing a no-fly zone and endorsing force to protect civilians.
Numerous bases around the Mediterranean could be involved in air strikes.
Attempting to head them off, Colonel Gaddafi’s government has declared a ceasefire and invited international observers.
The French foreign minister, Alain Juppé, said:
“We have to analyse the conditions of this ceasefire, it must be a ceasefire on the whole territory of Libya and not only on Benghazi, and we think that Libya must also comply with the whole resolution of the Security Council.”
The UN resolution means attacks could be launched not only against Libya’s air bases and air force, but against ground forces and other military targets too if civilians continue being threatened.
Those behind the moves at the UN are keen to get Arab nations involved.
The French ambassador said the United Arab Emirates and Qatar had agreed to send planes and pilots.
It is an international not a western operation, he added.