The fact that the Trusteeship Council was made a main organ of the UN is evidence of the importance attached to the role of the trusteeship system. The Council's functions, however, are decidedly more limited than those of the other main organs, for it acts, as the case may be, under the direct responsibility of the General Assembly in respect to trusteeships not involving areas designated as strategic or of the Security Council in respect to trusteeships relating to areas designated as strategic. The Charter provisions make it clear that the Trusteeship Council only "assists" the General Assembly and the Security Council in implementing the trusteeship system. It had a purely executive capacity in supervising the day-to-day operations of the system.
The Charter provides that the Council is to be composed of three groups of members: the countries administering trust territories, permanent members of the Security Council that do not administer trust territories, and a number of other UN members elected for three-year terms by the General Assembly to ensure an equal division between administering and nonadministering countries in the Council.
Until 1960, the Council consisted of 14 members: 7 administering members; 2 permanent nonadministering members; and 5 other nonadministering countries elected for three-year terms by the Assembly. As the various trust territories gained independence, the size and composition of the Council changed. The Assembly decided that after 1968, the Council would be composed only of administering powers and the nonadministering permanent members of the Security Council. On 16 September 1975, when Papua New Guinea, which includes the former trust territory of New Guinea, achieved independence, Australia ceased to be a member of the Council. This change left a membership of five: one administering power, the US, and four nonadministering permanent members of the Security Council—China, France, the USSR (today, the Russian Federation), and the UK.
Each member of the Trusteeship Council has one vote. Decisions are made by a simple majority vote. The permanent members of the Security Council have no veto or other special voting privileges. Before 1968, the Council held two regular sessions a year, and afterwards, one. Special sessions may be called on the decision of the majority of the members or at the request of the Security Council or the General Assembly. The president and vice-president are elected at the beginning of each regular session and serve for one year.
In carrying out its supervisory and administrative functions, the Council was specifically authorized under the Charter to consider reports submitted by the administering authority; to accept petitions and examine thin consultation with the administering authority; to provide for periodic visits to the trust territories at times agreeable to the respective administering authorities; and to formulate a questionnaire on the political, economic, social, and educational progress in each trust territory, which the administering authorities were required to answer.