In a statement after top defence committee meet, President Francois Hollande called on the European Union to speed up the deployment of an estimated 500 troops under the EUFOR mission.
The statement said the 400 new soldiers would include combat troops and gendarmes who would eventually be folded into the planned EU mission.
"France is calling on the international community to show increased solidarity with the Central African Republic," the statement said.
Amid concerns over mainly Christian militias attacking Muslims in the country, the statement said France would work to "stop the massacres, prevent war crimes and restore public security.