United Nations System
There are 15 members of the Security Council, consisting of five veto-wielding permanent members (China, France, Russia, the United Kingdom, and the United States) and 10 elected non-permanent members with two-year terms. This basic structure is set out in Chapter V of the UN Charter. Security Council members must always be present at UN headquarters in New York so that the Security Council can meet at any time.
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.