His distinguished diplomatic career spanned more than five decades, during which he held a number of senior portfolios in the Ethiopian Foreign Service, including as the first Ethiopian ambassador to Djibouti and as the permanent representative to the United Nations for Ethiopia, and as an official of the United Nations, including as Under-Secretary-General, Special Envoy for Sierra Leone, and Special Representative for the Great Lakes region and for Burundi.
[4] In May 1986, Berhanu was arrested and held as a political prisoner by the government of Mengistu Haile Mariam, after he was recalled from his assignment as ambassador to Canada and the United States.
[6] His release took place just five days before peace talks were due to begin in Atlanta, officiated by former U.S. President Jimmy Carter, between the Mengistu Haile Mariam regime and Eritrean rebels.
He served as the UN's representative at negotiations held in Arusha, Tanzania, as well as peace talks in Lusaka, Zambia, which were aimed at ending the conflicts in the Democratic Republic of the Congo.
[4] The African Union asked him to serve as the chairman of the Power-Sharing Commission, which concluded with the signing of the Darfur Peace Agreement in March 2006 in Abuja, Nigeria.