The concept is the UN Secretary-General, which is the chief administrative officer of the United Nations and the head of the UN Secretariat, one of the six principal organs of the UN. The current officeholder is António Guterres of Portugal, who is the ninth Secretary-General and took office on January 1, 2017. The position is a type of international civil service and diplomatic role, described as "equal parts diplomat and advocate, civil servant and CEO".
The office was created with the founding of the United Nations in 1945 to solve the problem of coordinating the complex administrative and diplomatic work of the new international body, which was established to maintain international peace and security. The role and the Secretariat are laid out in Chapter XV (Articles 97 to 101) of the UN Charter.
The mechanism for appointment is defined in Article 97 of the UN Charter, which states that the Secretary-General "shall be appointed by the General Assembly upon the recommendation of the Security Council". The term is typically five years and is renewable. Key functions include acting as the chief administrative officer (Article 97) and bringing to the attention of the Security Council any matter that may threaten international peace and security (Article 99). The Secretary-General also reports annually to the General Assembly on the work of the Organization (Article 98).
The role connects directly to the UN Security Council and the UN General Assembly, as the Secretary-General is tasked with balancing the demands of both and upholding the interests of underrepresented states. António Guterres was formally appointed on October 13, 2016, following a recommendation from the Security Council. The selection process for the Secretary-General has seen recent changes, with the 2016 selection being the first time candidates presented their platforms in public hearings before the General Assembly, a move intended to increase transparency. However, the core mechanism of appointment by the General Assembly upon the recommendation of the Security Council (Article 97) remains the same.