A French staff sergeant was killed in northern Mali early on Wednesday in an operation by French forces against "an armed terrorist group", President Francois Hollande's office said.
Hollande "expresses his deep respect for the sacrifice" of the officer during "a particularly perilous mission", the statement from the Elysee Palace said.
Defence Minister Jean-Yves Le Drian had earlier spoken of a "violent clash" between French-led forces and jihadists in the region.