President Francois Hollande said he “shared the grief of the families”. After his election last month, he announced French combat troops would leave Afghanistan by the end of 2012, two years before the main Nato pullout.
Violence has risen across the country in recent weeks, with the Taliban targeting both the Afghan forces and the 130,000 foreign troops remaining in the country. Afghan officials say the suicide bomber in Saturday’s attack approached a French Nato convoy wearing a burka.
“All of France is affected by this tragedy,” President Hollande’s statement said. France is currently the fifth largest contributor to Nato’s Isaf force, with nearly 3,300 soldiers.
The deaths bring to 87 the total number of French deaths in the country since 2001.
In January the killing of four French soldiers in Kapisa prompted then-President Nicolas Sarkozy to announce a withdrawal by the end of 2013.
Mr Hollande recently confirmed an election pledge to bring the pullout forward by a further year.