All the trust territories were administered through the United Nations Trusteeship Council and authorized to a single country.
The concept is distinct from a territory temporarily and directly governed by the United Nations.
South Africa's apartheid regime refused to commit to preparing the territory for independence and majority rule, as required by the trust territory guidelines, among other objections.
South-West Africa eventually gained independence in 1990 as Namibia.
The last was Palau, formerly part of the Trust Territory of the Pacific Islands, which became a member state of the United Nations in December 1994.