Pope John XXIII
Pacem in Terris §107
Pacem in Terris: On Establishing Universal Peace in Truth, Justice, Charity, and Liberty
107 We therefore take this opportunity of giving Our public approval and commendation to every undertaking, founded on the principles of human solidarity or of Christian charity, which aims at relieving the distress of those who are compelled to emigrate from their own country to another.
Source: Pacem in Terris (Vatican.va)