France said it was ready to dispatch about 1,000 troops to the Central African Republic to help avert "humanitarian chaos," possibly engaging force in yet another former French colony less than a year after sending its military to Mali.

French government officials said on Tuesday that Paris would send the additional contingent—about 450 French soldiers are already stationed in the country—once the United Nations Security Council has approved a broader mission aimed at stopping an outburst of ethnic violence in the...