ROME – Prominent Catholics, Pope Leo XIV and U.S. Vice President JD Vance, convened on Monday as part of a series of U.S.-initiated diplomatic activities aimed at achieving a ceasefire in the conflict between Russia and Ukraine.

Vance, a convert to Catholicism, was part of the U.S. team attending the ceremonial Mass that marked the beginning of the first American pope’s papacy. His motorcade was spotted entering Vatican City shortly after 7:30 a.m.

Joining Vance at the Vatican was Secretary of State Marco Rubio, also a Catholic, Vance spokesperson Luke Schroeder said.

Throughout the first three years of the conflict, the Vatican’s role was minimal. However, it has now expressed willingness to serve as a venue for peace discussions, all the while pursuing humanitarian actions for prisoner exchanges and the reunification of Ukrainian children abducted by Russia.

After greeting Leo briefly at the end of Sunday’s Mass, Vance spent the rest of the day in separate meetings with Ukrainian President Volodymyr Zelenskyy and EU Commission President Ursula von der Leyen.

Leo, the former Cardinal Robert Prevost, is a Chicago-born Augustinian missionary who spent the bulk of his ministry in Chiclayo, Peru, a commercial city of around 800,000 on Peru’s northern Pacific coast.

In the days since his May 8 election, Leo has vowed “every effort” to help bring peace to Ukraine. He also has emphasized his continuity with Pope Francis, who made caring for migrants and the poor a priority of his pontificate.

Before his election, Prevost shared news articles on X that were critical of the Trump administration’s plans for mass deportations of migrants.

Vance was one of the last foreign officials to meet with Francis before the Argentine pope’s April 21 death. The two had tangled over migration, with Francis publicly rebuking the Trump administration’s deportation plan and correcting Vance’s theological justification for it.

Later Monday, U.S. President Donald Trump has planned separate phone calls with Russian leader Vladimir Putin and Ukrainian President Volodymyr, as well as calls to NATO leaders.

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