The office of French President Francois Hollande said it was obligated to ensure "all enemies of peace" are fought effectively in CAR, a former French colony.
In a statement, the office said the addition of 400 troops would increase the number of French military personnel deployed in support of an African Union peacekeeping force to 2,000.
"France also called on the international community to act against the humanitarian emergency in CAR," the statement read. "It is a bounden duty of solidarity."
Hollande discussed the crisis in CAR Thursday with U.N. Secretary-General Ban Ki-moon during a visit to the United States.
The United Nations said Thursday it set aside $10 million in emergency humanitarian funds to support relief operations in CAR, one of the poorest nations in the world.
Seleka, a Sunni Muslim rebel coalition, overthrew the government in March. Chaos ensued when former President Michel Djotodia lost control of the rebel force. The crisis sparked attention from the International Criminal Court when anti-balaka, a Christian militia, took up arms against their Islamic rivals.
U.N. High Commissioner for Refugees Antonio Guterres said Wednesday the level of violence in CAR was "unspeakable." The ongoing crises in the country, he said, was "falling through the cracks of international attention" even though "massive ethno-religious cleansing is continuing."