The Charter describes the Secretary-General as "chief administrative officer" of the Organization, who shall act in that capacity and perform "such other functions as are entrusted" to him or her by the Security Council, General Assembly, Economic and Social Council and other United Nations organs.
The Charter also empowers the Secretary-General to "bring to the attention of the Security Council any matter which in his opinion may threaten the maintenance of international peace and security". These guidelines both define the powers of the office and grant it considerable scope for action.
The current Secretary-General, and the eighth occupant of the post, is Mr. Ban Ki-moon of the South Korea who took office on January 1, 2007. Secretaries-General serve for renewable five-year terms; most have served two terms.
- Trygve Lie (Norway) from February 1946 to November 1952.
- Dag Hammarskjöld (Sweden) from April 1953 until his death in a plane crash in Africa in September 1961.
- U Thant (Burma, now Myanmar) from November 1961 to December 1971.
- Kurt Waldheim (Austria) from January 1972 to December 1981.
- Javier Pèrez de Cuèllar (Peru) from January 1982 to December 1991.
- Boutros Boutros-Ghali (Egypt) from January 1992 to December 1996.
- Kofi Annan (Ghana) from January 1997 to December 2006.
The United Nations Secretariat
Assist the Secretary-General, and is a staff of international civil servants worldwide. It provides studies, information, and facilities needed by United Nations bodies for their meetings. It also carries out tasks as directed by the UN Security Council, the UN General Assembly, the UN Economic and Social Council, and other U.N. bodies.
The United Nations Charter provides that the staff be chosen by application of the "highest standards of efficiency, competence, and integrity," with due regard for the importance of recruiting on a wide geographical basis.