"Tomorrow I will go to the Foreign Affairs Council and I will ask that there be more solid, stronger support," Fabius said Sunday on Europe 1 radio.
Poland, Britain, Germany, Spain and Belgium are already helping with logistics, he said, and two countries are "currently considering" sending troops to back up the 1,600 soldiers there.
Nearly half of the 4.5-million population is in "pre-famine conditions", according to the minister, and there are only seven surgeons among that number.
"The Seleka... still have weapons and sometimes heavy weapons," he said. "So the first task is to disarm these heavy weapons. We also go to the Christians to say 'you must disarm'."
Right-wing former agriculture minister Bruno Le Maire expressed reservations about the intervention on Sunday.
He claimed that the political justification is "not clear" and that the cost will be high, while France is "alone", and called on President François Hollande to seek more money from the European Union and more troops from other countries through the United Nations.
Hollande has already pledged that he will ask for more European back-up at a summit on Thursday and Friday.