The latest French airstrike, on Monday night, hit Tal Afar, near the key city of Mosul, Le Drian told France Info radio.
"We don't announce it every day but since we are in the coalition we are striking every day," he said, referring to the US-led alliance engaged in an aerial campaign against IS.
Investigators have found that Nice attacker Mohamed Lahouaiej Bouhlel showed interest in IS shortly before he drove a lorry down Nice's Promenade des Anglais on Bastille Day, killing 84 people, and, although they have found no signs that he was in direct contact with the group, it claimed him as one of its "soldiers".
Defence ministers from countries in the anti-IS coalition will meet in Washington on Wednesday.
Le Drian said he expected theme to "push the offensive underway in Iraq and Syria to the limit" by concentrating strikes on the IS strongholds of Mosul in Iraq and Raqa in Syria.
Definitively eradicating IS will "take some more time", he said, adding that "striking in Mosul, striking in Iraq, is a way of ensuring our security in France and, more widely, in Europe."