Pope Leo XIV marked his first full day Friday as leader of the 1.4-billion-member Roman Catholic Church by celebrating Mass in the Vatican's Sistine Chapel with cardinals.

Preaching in the Sistine Chapel on May 9 to the cardinals who elected him, the first pope born in the United States opened his homily in English.

Pope Leo XIV, the first American pontiff, led his first mass as the new leader of the Catholic Church. Leo XIV held his first Mass as pope in the Sistine Chapel on Friday, in what was a private service for the 132 voting cardinals who elected him as the 267th leader of the world’s 1.4 billion Catholics a day earlier.