List of members of the United Nations Security Council
Membership of the United Nations Security Council is held by the five permanent members and ten elected, non-permanent members. Prior to 1966, there were six elected members, while the permanent members have in essence not changed since the creation of the United Nations in 1945, apart from the representation of China. Elected members hold their place on the Council for a two-year term, and half of these places are contested each year. To ensure geographical continuity, a certain number of members is allocated for each of the five UN regional groupings.In addition, one of the non-permanent members of the council is an Arab country, alternately from the African or Asia-Pacific groups. This rule was added to the system in 1967 for it to be applied beginning with 1968.
Charter of the United Nations
2. The non-permanent members of the Security Council shall be elected for a term of two years. In the first election of the non-permanent members after the increase of the membership of the Security Council from eleven to fifteen, two of the four additional members shall be chosen for a term of one year. A retiring member shall not be eligible for immediate re-election.