"If France takes any steps regarding its military presence in northern Syria, this would be an illegitimate step that would go against international law and in fact, it would be an invasion," Turkish Defense Minister Nurettin Canikli said Saturday.
The statement comes a day after Turkish President Recep Tayyip Erdogan accused France of supporting terrorists by "hosting them" at the Elysee Palace, referring to a delegation of Syrian Kurdish militia welcomed by the French authorities.
Last month, Turkey announced that a French promise to help stabilize a region of northern Syria controlled by Kurdish-dominated forces amounted to support for terrorism and could make France a "target of Turkey."
Ankara deployed soldiers in the northern Syrian region of Afrin on January 20 to carry out a military operation against Kurdish militants, members of the People's Protection Units (YPG), which the Turkish authorities accuse of having ties to the Kurdistan Workers' Party banned in Turkey as a terrorist organization.
France, which is active in Syria as part of the so-called US coalition, has slammed Ankara for the offensive.