The pope spoke to almost 100 apostolic nuncios and permanent observers of the Holy See who are meeting in Rome this week.
The 37th Apostolic Journey of Pope Francis, which will take him to Canada from July 24-30, is a "penitential pilgrimage” that may also help to heal and reconcile another relationship.
The pope was speaking to members of the Pontifical Ecclesiastical Academy.
The pope was giving his annual “state of the world” address.
The Holy See has been granted permanent observer status to the World Health Organization following resolution adopted by consensus on May 31.
In his annual address to diplomats Thursday, Pope Francis stressed that solidarity is needed in 2020 to overcome polarization for the sake of the poor, who suffer when the common good is disregarded.