The Trump administration has dispatched one of its top diplomatic officials to Africa this week, as it grapples with a brutal civil war in South Sudan that has unleashed the continent’s biggest refu­gee crisis since the 1994 Rwandan genocide.

Nikki Haley, the U.S. ambassador to the United Nations, began her three-nation swing Monday in Ethi­o­pia, but much of the focus of the trip will be on South Sudan.

Six years ago, with the help of the United States, South Sudan became the world’s newest nation, declaring independence from Sudan in a peaceful vote. But since the war erupted in late 2013, a third of South Sudan’s 12 million citizens either have fled the country or have been displaced internally. The fighting has left at least 50,000 dead and thousands targeted by sexual violence, and has created a hunger crisis that has tipped into famine in some places. The United Nations has reported that ethnic cleansing has taken place in some areas.