France is suspending its training programme and joint military operations with the army of Afghanistan after an Afghan soldier killed four French troops.
Another 16 French soldiers were injured in the incident in Kapisa province, the BBC reports.
An official told the BBC that an Afghan non-commissioned officer got into a "verbal clash" and opened fire.
French president Nicholas Sarkozy said he would also consider an early withdrawal of French troops from Afghanistan if he cannot be assured that security conditions are satisfactory.
France has almost 4000 troops in Afghanistan, fighting in some of the most dangerous areas, and are considered vital in the fight against Taliban.