United Nations Security Council
Along with the five permanent members, the Security Council of the United Nations has temporary members that hold their seats on a rotating basis by geographic region. Non-permanent members may be involved in global security briefings. In its first two decades, the Security Council had six non-permanent members, the first of which were Australia, Brazil, Egypt, Mexico, the Netherlands, and Poland. In 1965, the number of non-permanent members was expanded to ten.
United Nations Security Council Resolution 1645
The resolution then set out the composition of the commission, to include seven members of the Security Council, seven members of the United Nations Economic and Social Council, the top five providers to the United Nations budget, the top five providers to United Nations peacekeeping missions, with representation from all regional groups. It also discussed country-specific meetings of the commission, where representatives of the World Bank and International Monetary Fund, among others, could participate. The Peacebuilding Commission was encouraged to co-operate with international organisations as appropriate, and provide advice to the Council in matter with which it is seized.