Under the General Assembly's rules of procedure, the provisional agenda for a regular session must be issued no later than 60 days before the opening. However, up to 30 days before the opening, the Secretary-General, any of the other principal organs of the UN, or any member of the UN may request the inclusion of supplementary items. Additional items may also be included at any time if a majority of the General Assembly agrees.
Normally, the agenda includes well over 100 items. The great majority of substantive (that is to say, nonprocedural) items arise out of decisions made by previous sessions, and their inclusion in the agenda is automatic. Thus, the General Assembly frequently requests the Secretary-General, a special committee, or another UN organ to submit a special report on a given topic. The report, at the time that it is due, automatically becomes part of the agenda item on the topic. There also are several items that the General Assembly is obliged to consider at each session under the Charter—for example, the annual report of the Secretary-General on the work of the UN and the reports of the three councils.
The adoption of the agenda is not a mere formality. The General Assembly has to approve the entire agenda and may amend or delete any item by majority vote. A decision to reject a particular member's request to have an item placed on the agenda could have considerable political significance. It is the function of the General Committee (which could be described as the steering committee) to make recommendations to the General Assembly on the inclusion of requested items in the agenda. Most of the pros and cons of including a controversial item in the agenda are thrashed out in this committee rather than in plenary, and the committee's proceedings sometimes afford a preview of the positions that countries will take on certain questions when they come up for substantive debate. Another important function of the General Committee is to recommend the assignment of agenda items to the various main committees for debate. It may also recommend that an important item be debated in plenary without being referred to a committee.