The Secretary-General is appointed by the General Assembly, on the recommendation of the Security Council. The Secretary-General's selection is therefore subject to the veto of any of the five permanent members of the Security Council.
Mr. Ban Ki-moon, the eighth Secretary-General of the United Nations, took office on 1 January 2007. His predecessors were:
- Kofi A. Annan (Ghana), who held office from January 1997 to December 2006;
- Boutros Boutros-Ghali (Egypt), who held office from January 1992 to December 1996;
- Javier Pérez de Cuéllar (Peru), who served from January 1982 to December 1991;
- Kurt Waldheim (Austria), who held office from January 1972 to December 1981;
- U Thant (Burma, now Myanmar), who served from November 1961, when he was appointed acting Secretary-General (he was formally appointed Secretary-General in November 1962) to December 1971;
- Dag Hammarskjöld (Sweden), who served from April 1953 until his death in a plane crash in Africa in September 1961; and
- Trygve Lie (Norway), who held office from February 1946 to his resignation in November 1952.
Although there is technically no limit to number of five-year terms a Secretary-General may serve, none so far has held office for more than two terms.