There would be a genocide raging in Central African Republic if French troops had not been deployed, Foreign Minister Laurent Fabius said Tuesday ahead of a parliamentary vote to extend the military mission.

The issue has divided the French parliament but the vote to extend Operation Sangaris, whose mandate is due to expire in April, is expected to pass in both houses.

"If Operation Sangaris had not been launched there would have been genocide in the Central African Republic," Fabius said on France 2 television.

"The French were right to intervene," he said of the mission launched in December.

"We did it with the Africans of MISCA (the African Union force) and now the Europeans are coming to help us."

The number of French peacekeepers is expected to rise from 1,600 to 2,000 to support a 6,000-strong African Union force.

The European Union plans to send 1,000 troops to the strife-torn country. A French minister said the deployment would start next month.