Pope Leo The Vatican on Saturday named a veteran diplomat as its new ambassador to the United States, tasked with managing one of the Holy See’s most important bilateral relationships at a critical moment, strained by the Trump administration’s war with Iran and a crackdown on immigration.
Italian Archbishop Gabriele Caccia, 68, is currently the Holy See’s ambassador to the United Nations in New York. He succeeds French-born Cardinal Christophe Pierre, who retired at age 80 as nuncio to the Holy See in Washington.
Caccia serves as Nuncio to the Holy See lebanon Deployed to the United Nations in 2019. Caccia was ordained a priest in Milan in 1983 and later served as “evaluator” of the Vatican’s Secretariat of State, a key administrative position in the Holy See’s most important office.
At a time of global turmoil, he inherited a complex and important archive on the battle lines of church and state in the United States.
During Pierre’s tenure as nuncio, there were clear signs of friction between the U.S. Conference of Catholic Bishops, whose leadership leaned toward the conservative side and Pope Francis, who advocated for more progressive priorities.
Relations with the United States and its church are vital to the Holy See, not least because American Catholics are the most generous donors to the Holy See’s coffers.
Leo, the first American-born pope in history, is well aware of this dynamic, having served for two years as a key figure in Francis’s nomination of bishops before being elected in 2025. Leo emphasized the message of peace and unity in the Church.
Trump’s first administration clashed with Francis over immigration, and the tensions continued during Leo’s pontificate and Trump’s second term. Leo has repeatedly insisted that the Trump administration respects the human dignity of immigrants while recognizing their rights at the border.
Recently, Leo expressed “deep concern” about the US-Israeli war in Iran and urged both sides to “stop the escalation of violence before it spirals into an abyss of no return.”
Leo called for a return to diplomacy in comments on Sunday. Weapons only cause “destruction, suffering and death,” he said.
In a major foreign policy speech earlier this year, Leo also made clear his opposition to the United States’ aggressive use of military force, an apparent reference to Washington’s invasion of Venezuela and threats to occupy Greenland. He condemned how countries use force to assert their dominance around the world and “totally undermine” peace and the post-World War II international legal order.
Cassia said in a statement on Saturday that he was humbled by Leo’s appointment and the confidence placed in him to serve as ambassador to his home country.
“I accepted this mission with joy and trepidation,” Vatican News reported. His mission, he said, was “to serve communion and peace,” recalling that this year marks the 250th anniversary of America’s independence.
Archbishop Paul S. Coakley, current president of the U.S. Conference, welcomed Cassia’s appointment and offered the U.S. leadership “the warmest welcome and our prayerful support.”
The Holy See has a tradition of diplomatic neutrality, although Leo strongly opposed Israel’s military operations in Gaza and the humanitarian damage caused by Russia’s invasion of Ukraine.
