The membership of the United Nations comprises the sovereign states that have been admitted to the Organization since its founding in 1945. Membership confers the ability to participate fully in the UN’s principal bodies and processes, and it signals broad international recognition. The UN keeps an up-to-date roster with the date each country joined; see the official UN member list for the complete register.

Admission criteria and process

Admission is governed by the UN Charter and requires that an applicant be a peace-loving state that accepts and is able to carry out the obligations of the Charter. In practice, a state applies for membership, the Security Council considers the request and must recommend admission, and the General Assembly then votes to admit the state. Some categories of entities—such as non-member observers—have different, limited statuses.

Rights, responsibilities and participation

Member states have the right to sit in the General Assembly, vote on resolutions and participate in specialized agencies, peacekeeping operations and treaty negotiations. Membership also brings responsibilities: contributing to collective security measures, abiding by Security Council decisions, providing financial contributions and engaging in diplomacy. Practical influence varies with a state’s diplomatic capacity and roles within UN organs.

History and development

The UN was established in the aftermath of the Second World War, with the Charter signed in 1945. The organization began with a smaller group of founding members and expanded rapidly in the decades that followed, especially during decolonization in the mid-20th century and after the end of the Cold War. New admissions continue to reflect changes in sovereignty and statehood; for example, the most recent addition to the membership occurred in the early 21st century.

Observers, special cases and notable facts

  • Observer entities: Certain non-member entities participate with observer status, which allows them to attend General Assembly meetings but not vote. The Holy See (Vatican) and the State of Palestine are prominent examples.
  • Succession and continuity: When a predecessor state dissolves or changes form, its UN seat can be succeeded by a successor state under political and legal arrangements, a situation that has occurred in modern history.
  • Rare sanctions: Formal expulsion or suspension of membership is extremely uncommon; the Charter provides mechanisms but they have seldom been applied.

Lists of member states typically include each country’s formal name and the date of admission; such lists are used by diplomats, scholars and governments to verify recognition, voting eligibility and treaty participation. For the current, authoritative roster and accession dates consult the official UN member list.