Answering questions in parliament, Ayrault said French forces would not have to bear the burden of fighting in Mali for very long.

"France is today in the vanguard, but within a week African forces will start to deploy on the ground," Ayrault said.

French warplanes have been hitting targets in various parts of Mali since Friday in support of Malian forces seeking to dislodge Islamist rebels who last year seized control of its vast desert north and had advanced south.

France has deployed 750 soldiers to the country and defence sources said it planned to boost its presence to a total of 2,500 troops.

The rebels have abandoned several key strongholds under the French onslaught.

"We brought a halt to the (rebel) offensive," Ayrault said, though he warned that the rebels' "determination remains intact".

France's National Assembly and Senate on Tuesday each held a minute of silence in memory of a French helicopter pilot killed Friday in Mali and another servicemen killed Saturday in a failed attempt to rescue a French hostage held by the Al-Qaeda-linked Shebab in Somalia.

At a military memorial service for the pilot, 41-year-old Damien Boiteux, at the Les Invalides military monument, Ayrault praised his "exceptional courage" and said he had "died for France".

"We pay homage to your commitment, that of a life devoted to the defence of our country. This commitment led to the ultimate sacrifice. It will not be forgotten," Ayrault said.