1976-77, Minister of Scientific Research; 1977-79, Minister of Mines and Energy, in charge of scientific research; 1979-84, Minister of Mines and Energy; 1984-88, Minister of Mines and Hydrocarbons; 1988-91, Minister of Higher Education, in charge of scientific research; 1991-97, Adviser to President Denis Sassou Nguesso; 1997-2005, Minister of Foreign Affairs and Co-operation; 2005-07, Minister of State and Minister of Foreign Affairs and Francophonie; 2007-09, Joint Special Representative, UN and African Union for Darfur; since September 2009, current position.