The French government says its troops will stay in Mali, west Africa, at least until July.
It had promised to leave this month—but said that Islamic rebels have put up a tougher fight than expected.
A French paratrooper was killed last Saturday, the third French soldier to die since the invasion began in January.
France has not announced how many rebels or civilians have died.
The French government claimed it had killed two leaders of Al Qaida in the Islamic Maghreb—Abou Zeid and Mokhtar Belmokhtar.
But it has no confirmation of the deaths.
Belmokhtar organised a recent attack on a gas plant in Algeria.
British foreign secretary William Hague arrived in the Malian capital, Bamako, last Monday to show his support for the intervention.
But in northern cities shops, banks, and food markets remain closed. Very few of the Tuaregs and Arabs who ran much of the trade remain.
Schools that closed when the French invaded are starting to reopen. But many teachers and pupils have fled.