Pope Gregory XVI, Summo Iugiter Studio, May 27, 1832, on no salvation outside the Church: “You know how zealously Our predecessors taught that article of faith which these dare to deny, namely the necessity of the Catholic faith and of unity for salvation… Omitting other appropriate passages which are almost numberless in the writings of the Fathers, We shall praise St. Gregory the Great who expressly testifies that THIS IS INDEED THE TEACHING OF THE CATHOLIC CHURCH. He says: ‘The holy universal Church teaches that it is not possible to worship God truly except in her and asserts that all who are outside of her will not be saved.’ Official acts of the Church proclaim the same dogma. Thus, in the decree on faith which Innocent III published with the synod of Lateran IV, these things are written: ‘There is one universal Church of all the faithful outside of which no one is saved.’ Finally the same dogma is also expressly mentioned in the profession of faith proposed by the Apostolic See, not only that which all Latin churches use, but also that which… other Eastern Catholics use. We did not mention these selected testimonies because We thought you were ignorant of that article of faith and in need of Our instruction. Far be it from Us to have such an absurd and insulting suspicion about you. But We are so concerned about this serious and well known dogma, which has been attacked with such remarkable audacity, that We could not restrain Our pen from reinforcing this truth with many testimonies.”
Pope Eugene IV, The Council of Florence, “Exultate Deo,” Nov. 22, 1439: “Holy baptism, which is the gateway to the spiritual life, holds the first place among all the sacraments; through it we are made members of Christ and of the body of the Church. And since death entered the universe through the first man, ‘unless we are born again of water and the Spirit, we cannot,’ as the Truth says, ‘enter into the kingdom of heaven’ [John 3:5]. The matter of this sacrament is real and natural water.”
(and as you probably already know, The Pope is infallible and His words are guided by the Will of God, The Holy Ghost.)