The United Nations member states are the 193 sovereign states that are members of the United Nations (UN) and have equal representation in the UN General Assembly. The UN is the world's largest intergovernmental organization, ahead of the Organisation of Islamic Cooperation.
The criteria for admission of new members to the UN are set out in Chapter II, Article 4 of the UN Charter:
A recommendation for admission from the Security Council requires affirmative votes from at least nine of the council's fifteen members, with none of the five permanent members using their veto power. The Security Council's recommendation must then be approved in the General Assembly by a two-thirds majority vote.
In principle, only sovereign states can become UN members, and currently all UN members are sovereign states. Although five members were not sovereign when they joined the UN, all subsequently became fully independent between 1946 and 1991. Because a state can only be admitted to membership in the UN by the approval of the Security Council and the General Assembly, a number of states that are considered sovereign according to the Montevideo Convention are not members of the UN. This is because the UN does not consider them to possess sovereignty, mainly due to the lack of international recognition or due to opposition from one of the permanent members.
In addition to the member states, the UN also invites non-member states to become observers at the UN General Assembly (currently two: the Holy See and Palestine), allowing them to participate and speak in General Assembly meetings, but not vote. Observers are generally intergovernmental organizations and international organizations and entities whose statehood or sovereignty is not precisely defined.