As Pope Leo XIV is formally inaugurated, he vows to work for unity and peace at a time of polarization in the Catholic Church and the wider world, with leaders including Vice President Vance and Ukraine's Zelensky in attendance.

"Welcome his word that enlightens and consoles! Listen to his offer of love and become his one family: 'In the one Christ, we are one.'"

Presiding over a Mass in St. Peter’s Square on Sunday, Leo was inaugurated as the first American pope, in a ceremony filled with ancient and symbolic rituals.