43 Our hope for the return of these brothers and sons separated from the Apostolic See is made stronger by this harsh crucifixion and these bloody martyrdoms of so many other brothers and sons. Let no one neglect or impede the saving work of God. To the blessings and joys of this return we exhort and urge all those who follow the erroneous doctrines of the Nestorians and the Monophysites. Let them be sure that we should think it the brightest gem in the crown of our apostolate if the opportunity were given us of treating with honor and charity those who are the more dear to us because the long period of their withdrawal has excited in us the greater desire [for their return].
Source: Sempiternus Rex Christus (Vatican.va)