US Secretary of State Anthony Blinken was expected in Kenya on Monday as he begins his first visit to Africa as Washington's top diplomat.
Blinken will also travel to Nigeria before ending his trip in Senegal later this week.
In Nairobi, he's expected to discuss with President Uhuru Kenyatta the crisis in Sudan and Ethiopia.
American diplomacy has so far failed to achieve results in Khartoum, where the army overthrew a transitional administration last month, and in Addis Ababa, where fighting between government forces and TPLF rebels has grown more violent.
US Horn of Africa envoy Jeffrey Feltman has been to the region several times but the situation in both countries has not changed.
President Kenyatta was in Addis Ababa on Sunday where he held talks with Prime Minister Abiy Ahmed.