The United Nations Atomic Energy Commission (UNAEC) was founded on 24 January 1946 by the very first resolution of the United Nations General Assembly "to deal with the problems raised by the discovery of atomic energy."The General Assembly asked the Commission to "make specific proposals: (a) for extending between all nations the exchange of basic scientific information for peaceful ends; (b) for control of atomic energy to the extent necessary to ensure its use only for peaceful purposes; (c) for the elimination from national armaments of atomic weapons and of all other major weapons adaptable to mass destruction; (d) for effective safeguards by way of inspection and other means to protect complying States against the hazards of violations and evasions."On 14 December 1946, the General Assembly passed a follow-up resolution urging an expeditious completion of the report by the Commission as well as its consideration by the United Nations Security Council. The Security Council received the report on 31 December 1946 and passed a resolution on 10 March 1947, "recognizing that any agreement expressed by the members of the Council to the separate portions of the report is preliminary" and requesting a second report to be made. On 4 November 1948, the General Assembly passed a resolution stating that it had examined the first, second and third reports of the Commission and expressed its deep concern at the impasse which had been reached, as shown in its third report.On 14 June 1946, the United States representative to the Commission, Bernard Baruch, presented the Baruch Plan, wherein the United States (at the time the only state possessing atomic weapons) would destroy its atomic arsenal on the condition that the U.N. imposed controls on atomic development that would not be subject to United Nations Security Council veto. These controls would allow only the peaceful use of atomic energy. The plan was passed by the Commission, but not agreed to by the Soviet Union who abstained on the proposal in the Security Council. Debate on the plan continued into 1948, but by early 1947 it was clear that agreement was unlikely.The UN General Assembly officially disbanded UNAEC in 1952, although the Commission had been inactive since July 1949.

The United Nations General Assembly (UNGA or GA; French: Assemblée générale, AG) is one of the six principal organs of the United Nations (UN), serving as the main deliberative, policymaking, and representative organ of the UN. Currently in its 76th session, its powers, composition, functions, and procedures are set out in Chapter IV of the United Nations Charter. The UNGA is responsible for the UN budget, appointing the non-permanent members to the Security Council, appointing the Secretary-General of the United Nations, receiving reports from other parts of the UN system, and making recommendations through resolutions. It also establishes numerous subsidiary organs to advance or assist in its broad mandate. The UNGA is the only UN organ wherein all member states have equal representation.

The General Assembly meets under its president or the UN Secretary-General in annual sessions at UN headquarters in New York City; the main part of these meetings generally run from September to part of January until all issues are addressed (which is often before the next session starts). It can also reconvene for special and emergency special sessions. The first session was convened on 10 January 1946 in the Methodist Central Hall in London and included representatives of the 51 founding nations.

Voting in the General Assembly on certain important questions—namely recommendations on peace and security; budgetary concerns; and the election, admission, suspension or expulsion of members—is by a two-thirds majority of those present and voting. Other questions are decided by a simple majority. Each member country has one vote. Apart from the approval of budgetary matters, including the adoption of a scale of assessment, Assembly resolutions are not binding on the members. The Assembly may make recommendations on any matters within the scope of the UN, except matters of peace and security under the Security Council consideration.

During the 1980s, the Assembly became a forum for "North-South dialogue" between industrialized nations and developing countries on a range of international issues. These issues came to the fore because of the phenomenal growth and changing makeup of the UN membership. In 1945, the UN had 51 members, which by the 21st century nearly quadrupled to 193, of which more than two-thirds are developing. Because of their numbers, developing countries are often able to determine the agenda of the Assembly (using coordinating groups like the G77), the character of its debates, and the nature of its decisions. For many developing countries, the UN is the source of much of their diplomatic influence and the principal outlet for their foreign relations initiatives.

Although the resolutions passed by the General Assembly do not have the binding forces over the member nations (apart from budgetary measures), pursuant to its Uniting for Peace resolution of November 1950 (resolution 377 (V)), the Assembly may also take action if the Security Council fails to act, owing to the negative vote of a permanent member, in a case where there appears to be a threat to the peace, breach of the peace or act of aggression. The Assembly can consider the matter immediately with a view to making recommendations to Members for collective measures to maintain or restore international peace and security.