Pope John XXIII
Pacem in Terris §137
Pacem in Terris: On Establishing Universal Peace in Truth, Justice, Charity, and Liberty
137 Today the universal common good presents us with problems which are world-wide in their dimensions; problems, therefore, which cannot be solved except by a public authority with power, organization and means co-extensive with these problems, and with a world-wide sphere of activity. Consequently the moral order itself demands the establishment of some such general form of public authority.
Source: Pacem in Terris (Vatican.va)