Tens of thousands came to St. Peter’s Square to mark the official start of the pontificate of the first American to lead the Roman Catholic Church. Vice President JD Vance was among the dignitaries who attended.

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.

This is the missionary spirit that must animate us; not closing ourselves off in our small groups, nor feeling superior to the world,” Pope Leo said during the Mass on Sunday