Secretary-General of the United Nations the appointee's national origin and to gender equality, although no woman has yet served as Secretary-General. The length of the term is discretionary, but all Secretaries-General since 1971 have been appointed to five-year terms. Every Secretary-General since 1961 has been re-selected for a second term, with the exception of Boutros Boutros-Ghali, who was vetoed by the United States in the 1996 selection. There is a term limit of two full terms, established when China cast a record 16 vetoes against Kurt Waldheim's third term in the 1981 selection. No Secretary-General since 1981 has attempted to secure a third term. The
Under-Secretary-General of the United Nations independent of the Secretary-General, and he is therefore unable to remove them from office without the General Assembly's consent. This restriction has been seen by many commentators to weaken the Secretary-General's ability to provide strong leadership and management within the United Nations System. Some senior posts within the UN System have the equivalent rank of Under-Secretary-General but are either not entitled or choose not to use the formal title. The most prominent example of this is the Administrator of the United Nations Development Programme, who is often referred to as the third most senior official within the UN System yet