Since August 2013 , he is U.S. Special Envoy to Sudan and South Sudan .
Donald E. Booth is an American diplomat , who has been ambassador of the United States to Liberia , Zambia , and Ethiopia .
Since August 2013 , Donald E. Booth is United States Special Envoy to Sudan and South Sudan .
Donald E. Booth is an American diplomat , who has been ambassador of the United States to Liberia , Zambia , and Ethiopia .