World leaders arrived in the Vatican on Sunday (May 18) as Pope Leo, the first American to head the global Catholic Church, is set to be inaugurated at a Mass.

Leo, who was elected in a conclave that ended on May 8, will be officially installed as the new leader of the world’s 1.4 billion Roman Catholics on Sunday.

United States Vice President JD, as well as Ukraine’s Volodymyr Zelenskiy, were present at Sunday's event.

Cardinal Robert Prevost, a Chicago native, succeeds Pope Francis, who died on April 21 aged 88.

Leo has already pledged to make "every effort" for peace and offered the Vatican as a mediator in global conflicts. His first words to crowds in St Peter's Square were "Peace be with all of you."

DESCRIPCIÓN DE IMÁGENES

VATICAN CITY (MAY 18, 2025) (VATICAN MEDIA - Access all)

1. DIGNITARIES ARRIVING IN VATICAN FOR POPE LEO’S INAUGURAL MASS

2. ITALIAN PRESIDENT SERGIO MATTARELLA TALKING TO ATTENDEES

3. ITALIAN PRIME MINISTER GIORGIA MELONI ARRIVING SHAKING HANDS WITH OTHERS

4. ST. PETER'S SQUARE AS WORLD DIGNITARIES ARRIVE AND TAKE THEIR SEATS

5. MONACO’S PRINCE ALBERT AND HIS WIFE PRINCESS CHARLENE (WHITE DRESS AND WHITE HEAD SCARF) GREETING PEOPLE AS TAKING THEIR SEATS

6. U.S. VICE PRESIDENT JD VANCE AND HIS WIFE, USHA VANCE, ARRIVING AND SHAKING HANDS WITH OTHERS

7. DIGNITARIES TAKING THEIR SEATS

8. U.S. VICE PRESIDENT JD VANCE AND HIS WIFE, USHA VANCE, STANDING IN THE CROWD

9. VARIOUS OF UKRAINIAN PRESIDENT VOLODYMYR ZELENSKIY AND HIS WIFE OLENA ZELENSKA ARRIVING, GREETED BY OTHERS SHAKING HANDS

VATICAN CITY (MAY 18, 2025) (REUTERS - Access all)(MUTE)

10. STILL OF GERMANY'S CHANCELLOR FRIEDRICH MERZ ARRIVES