A meeting of the United Nations Security Council is to be held to discuss the situation in Mali, following a request from France.
French fighter jets pounded Islamist rebel strongholds deep in northern Mali last night as France sent more troops into the capital Bamako.
It is awaiting a west African force to dislodge al-Qaeda-linked insurgents from the country's north.
French President Francois Hollande's intervention won plaudits from leaders in Europe, Africa and the US, but it is not without risks.
The attacks on Islamist positions near the ancient desert trading town of Timbuktu and Gao, the largest city in the north, marked a decisive intensification on the third day of the French mission.
France is determined to end Islamist domination of northern Mali, which many fear could act as a base for attacks on the West and for links with al-Qaeda in Yemen, Somalia and north Africa.
Mr Hollande said France's aim is simply to support a mission by west African bloc ECOWAS to retake the north, as mandated by a UN Security Council resolution in December.
With France pressing west African nations to send their troops quickly, Ivory Coast President Alassane Ouattara, who holds the rotating ECOWAS chairmanship, kick-started the operation to deploy 3,300 African soldiers.
Mr Ouattara, installed in power with French military backing in 2011, convened a summit of the 15-nation bloc in Ivory Coast to discuss the mission.
The US is providing transportation and communications support for the push against the Islamist rebels, a US official has said, speaking on condition of anonymity.
The US support also includes intelligence sharing, the official said, without elaborating.
Earlier yesterday, another US official said it is considering sending a small number of unarmed surveillance drones.
Britain and Canada have also promised logistical support.
France's Defence Minister Jean-Yves Le Drian said France's sudden intervention on Friday had prevented the advancing rebels from seizing Bamako. He vowed that air strikes would continue.
"The president is totally determined that we must eradicate these terrorists who threaten the security of Mali, our own country and Europe," he told French television.
Residents and rebel leaders had reported air raids early yesterday in the towns of Lere and Douentza in central Mali, forcing Islamists to withdraw.
As the day progressed, French jets struck targets further to the north, including near the town of Kidal, the epicentre of the rebellion.
In Gao, a town on the banks of the Niger river where Islamists have imposed an extreme form of sharia law, residents said French jets pounded the airport and rebel positions.
A huge cloud of black smoke rose from the militants' camp in the city's north, and trucks ferried dead and wounded to hospital.
Four Rafale jets flew from France to strike rebel training camps, logistics depots and infrastructure around Gao with the aim of weakening the rebels and preventing them from returning southward.
France has deployed about 550 soldiers to Mali under "Operation Serval" - named after an African wildcat - split between Bamako and the town of Mopti, 500km north.