The UN chief told reporters today he is "gravely concerned about the imminent danger of mass atrocities" in the country which "descended into chaos" this year.
Mainly Muslim rebels overthrew the Christian-led government in March.
Ban said the entire population of 4.6 million people half of them children is affected, and the UN is scaling up its humanitarian response and sending in human rights monitors.
He said African and French troops are already making a difference but "we must do more to meet this test of global solidarity.