Pope Leo XIV, the first American pontiff for the Roman Catholic Church, will celebrate his inaugural mass on Sunday, according to the Vatican.

Pope Leo XIV will preside over his inaugural mass today in front of St Peter’s Basilica, which marks the formal start of his papacy. JD Vance, Marco Rubio and Volodymyr Zelenskyy are attending.

Pope Leo XIV’s inauguration Mass on Sunday morning at St. Peter’s Square is an ancient ritual filled with symbolism that connects back to Peter, Jesus’ apostle, and his special mission as head of the Catholic Church.