Pope Leo XIV, recently elected, is set to conduct his inaugural mass this Sunday. Tens of thousands are expected to witness the event, with notable attendees including Vice President JD Vance and Ukrainian President Volodymyr Zelensky.

Taking place at 4 a.m. New York time, and 10 a.m. locally, the mass will be held in St. Peter’s Basilica and Square in Vatican City. This event marks the official installation of the first pope from the United States as the head of the global Roman Catholic community, which numbers 1.4 billion.

During the ceremony, the pope will receive the “Ring of the Fisherman,” a gold signet ring crafted exclusively for a newly selected pope, as confirmed by the Vatican Press Office.

He will also be draped in a new ceremonial-type garment known as a Petrine Pallium, which is meant to signify him carrying the responsibility of shepherding the entire church on his shoulders.

Tens of thousands are expected to flock to Vatican City for the grand occasion, while scores of world leaders are slated to be inside the Basilica for the mass.

Vice President Vance will lead the US delegation, which will also include Secretary of State Marco Rubio, House Majority Leader Steve Scalise, R-Louisiana, and a host of other members of Congress.

Ukraine’s President Volodymyr Zelensky, who infamously clashed with Vance during their White House sit-down in February, is expected to be among the notable world leaders in attendance.

A Zelensky aide said earlier this week the Ukrainian president would be happy to meet other leaders on the sidelines of the mass after Pope Leo vowed to personally make “every effort” to help end the Russia-Ukraine war.

Zelensky, for his part, held face-to-face talks with President Trump in St. Peter’s Basilica when they both attended Pope Francis’ funeral last month.

Rubio on Saturday signaled the Vatican could be a venue for peace talks.

Speaking to reporters in Rome before sitting down with Cardinal Matteo Zuppi, the Vatican point man for Ukraine, Rubio said he wanted to find potential ways the Vatican could help with a “path forward.”

Asked if the Vatican could be a peace broker, Rubio responded: “I wouldn’t call it broker, but it’s certainly — I think it’s a place that both sides would be comfortable going.”

“So we’ll talk about all of that and obviously always grateful to the Vatican for their willingness to play this constructive and positive role,” he added.

Among other leaders expected on Sunday are the presidents of Israel, Peru and Nigeria, the prime ministers of Italy, Canada and Australia, German Chancellor Friedrich Merz and European Commission President Ursula Von der Layen.

Many European royals will also be present, including Spain’s King Felipe and Queen Letizia.

Russia will be represented by Culture Minister Olga Lyubimova, the Vatican said.

With Post wires