Jean-Yves Le Drian told French radio station Europe 1 that French troops would act only "in support" of an African stabilisation force in the Central African Republic and "for a short period, in the range of about six months."
France’s ambassador to the United Nations said the French would provide a “bridging force” to restore some order and protect civilians but that the African stabilisation force would quickly take over that job.
Central African Republic Prime Minister Nicolas Tiangaye said after talks in Paris on Monday that Foreign Minister Laurent Fabius had talked of adding 800 troops to the 410 French soldiers already based in the capital, Bangui.
Tiangaye said "serious war crimes" are being committed in his country, where rebels forced President Francois Bozize to flee in March.
A transitional government has since lost control of the country of 4.5 million people.
France on Monday proposed a UN Security Council resolution authorising international troops to use force to end mounting chaos in the country.
The resolution, which would also impose an arms embargo on the strife-torn country, could be passed by the 15-member Security Council next week.