In his New Year speech to the armed forces in Toulouse, in southern France, Macron said Thursday President Donald Trump's decision "must not make us deviate from our goal: eradicating Daesh." He used the Arabic acronym to refer to the Islamic State group.
He added: "Any hasty decision to withdraw would be a mistake."
France has been involved in Syria since 2015, mostly through airstrikes, as a member of the international coalition fighting IS.
Macron also expressed support for French troops fighting extremism in Africa and protecting France against terrorism at home.
He reiterated his ambition to establish a European military force for rapid intervention in case of conflict.