"During a support mission with the Afghan National Army (ANA) in the Tagab valley, the two non-commissioned officers were mortally wounded by deliberate fire from an Afghan soldier," a statement said.
NATO`s US-led International Security Assistance Force had earlier announced the death of the two soldiers without giving their nationality.
The Taliban claimed responsibility for the attack, which it said targeted French troops in Kapisa province, east of the capital Kabul.
The group, which has been waging a 10-year insurgency against ISAF and Afghan forces, also said it was behind a roadside bomb attack in the southern province of Helmand that killed 10 local police.
In the statement, French President Nicolas Sarkozy expressed "France`s determination to continue working within the International Security Assistance Force to re-establish peace and stability" in Afghanistan.
French Defence Minister Gerard Longuet said the incident would not affect France`s cooperation with the ANA.
"This isolated incident does not in any way call into question the transition process aimed at handing over security responsibilities to the Afghan National Army," he said.
The two deaths brought to 78 the number of French soldiers killed in Afghanistan since French forces deployed there at the end of 2001. This year has been the bloodiest so far, with 26 killed.
France has about 3,700 soldiers serving in the country, mainly in the provinces of Kabul and Kapisa.