Pope Leo XIV holds first mass after greeting crowds in St. Peter's Square LIVE

On Sunday morning, Pope Leo XIV rode in an open-topped popemobile through St. Peter's Square, where thousands gathered ahead of his inaugural mass, News.Az informs via ABC News.

The Holy Mass for the Beginning of the Pontificate began at 10 a.m. local time in St. Peter’s Basilica.

Attendees at the mass, which marks the official beginning of Leo’s papacy, included Vice President JD Vance and Secretary of State Marco Rubio, along with other political figures and religious dignitaries. Vance and Ukrainian President Volodymyr Zelenskyy greeted each other and shook hands prior to the mass.

Ukraine's President Volodymr Zelenskyy, left, and Vice President JD Vance greet each other as Secretary of State Marco Rubio, center, looks on ahead of Pope Leo XIV's formal inauguration of his pontificate with a Mass in St. Peter's Square attended by heads of state, royalty and ordinary faithful, Sunday, May 18, 2025.

Gregorio Borgia/AP

Representatives of the Ecumenical, Jewish, Muslim, Hindu, Buddhist, Sikh, Zoroastrian and Jain churches were in attendance, the Vatican's Holy See press office said.

Leo, who was formerly Cardinal Robert Prevost, is a 69-year-old native of Chicago, Illinois. Elected on May 8, he's the first American to lead the church.

Pope Leo XIV on his popemobile tours St. Peter's Square at the Vatican prior to the inaugural Mass of his pontificate, Sunday, May 18, 2025.

Andrew Medichini/AP

Pope Francis, his predecessor, died on April 21, after he was discharged from a weeks-long hospital stay.