Months of abuses by the president’s mainly Muslim rebels led to the creation of Christian defence militia.
After the coup, heavily armed rebels carried out atrocities against civilians, with reports of people being tied together and thrown off bridges leaving hundreds dead.
French soldiers and African Union peacekeepers have struggled to restore order in the former French colony.
European Union governments broadly backed proposals on Friday for the EU to quickly send troops to help.
The EU ambassadors, meeting in Brussels, asked EU foreign policy chief Catherine Ashton to present a more detailed paper next week, with a view to EU foreign ministers taking a decision on the force on January 20, a spokesman for Ashton said.
Belgium has said it would consider putting boots on the ground as part of an EU operation.