A nuncio is not simply a "diplomat in a (priest's) collar," but must truly be a priest and bishop who listens, supports and serves as a channel of God's mercy, Pope Francis said.

Spending much of the day on September 17 with 106 archbishops who represent him and the Vatican in countries around the world, Pope Francis thanked the nuncios for their constant willingness to pack up, move to a new country, learn a new language and deal with new challenges.

And, he said, he knew that every four or five years they get another "sugarcoated" phone call from Rome and do it all again.