In Southern Africa, Tempelsman has played a key role in negotiations between hostile governments and companies engaging in diamond exploration. He met with Mobutu Sese Seko, to assist the regime's business dealings with De Beers. In the 1960s Tempelsman hired as his business agent the CIA station chief in Kinshasa, Larry Devlin, who helped put Mobutu in power and afterward served as his personal adviser. From March 3, 1977, Tempelsman briefly held the title of honorary consul general for Zaire, now known as the Democratic Republic of Congo (DRC), at the DRC's consular offices in New York City. In addition to the DRC, Tempelsman has played a key role in the diamond industries of Angola, Botswana, Namibia, and Sierra Leone.