UNITED NATIONS  – Pakistan, Azerbaijan, Guatemala, Morocco and Togo, the five new non-permanent members of the 15-nation UN Security Council, on Sunday began to serve their two-year terms.

The five new Council members were elected by the UN General Assembly in October 2011. The five represent different geographical groups - three from Africa and the Asia-Pacific region, one from Eastern Europe, and one from Latin America and the Caribbean.

Lebanon, Nigeria, Gabon, Bosnia and Brazil are ending their terms on the Council on Sunday. The five temporary members that will remain through 2012 are Colombia, Germany, India, Portugal and South Africa. Under the UN Charter, the Security Council, the most powerful UN body, has the primary responsibility for the maintenance of international peace and security. The Council has 15 members: five permanent - China, France, Russia, the United Kingdom and the United States — and 10 elected by the UN General Assembly for two-year terms.

Each member has one vote. Decisions on procedural matters are made by an affirmative vote of at least nine of the 15 members. Decisions on substantive matters require nine votes and the absence of a negative vote by any of the five permanent members.

Under Article 25 of the UN Charter, all members of the United Nations agree to accept and carry out the decisions of the Security Council. While other organs of the United Nations make recommendations to member states, the Council alone has the power to take decisions which member states are obliged under the Charter to implement.