The United Nations regards the rank as equal to that of a cabinet minister of a member state, and under-secretaries-general have diplomatic immunity under the UN Charter.

This restriction has been seen by many commentators to weaken the secretary-general's ability to provide strong leadership and management within the United Nations System.

The most prominent example of this is the administrator of the United Nations Development Programme, who is often referred to as the third most senior official within the UN System yet does not use the title of under-secretary-general.

The most important USGs, controlling budgets, programmes or key activities, are also members of the United Nations Senior Management Group, whose objective is to ensure strategic coherence and direction in the work of the organization.

The cabinet was approved by the General Assembly in 1997 as part of the reform proposal submitted by Secretary-General Kofi Annan.