3 The happy day has not yet come on which, all the peoples of the East returning to the fold, we should be able to embrace them all with the affection of the father. Nonetheless we have the happiness of seeing not a few of our sons from those countries; these, since they have recognized the Chair of Peter as the center of Catholic unity, persevere with the greatest tenacity in defending and strengthening this same unity.
Source: Orientales Omnes Ecclesias (Vatican.va)