"Pope Francis always is willing to welcome heads of state who ask," Archbishop Angelo Becciu, Vatican substitute secretary of state, told the Italian news agency ANSA April 19.
Trump is scheduled to be in Taormina, in southern Italy, May 26-27 for a summit of G-7 leaders and representatives of the European Union.
Sean Spicer, White House spokesman, told reporters April 19, "We will be reaching out to the Vatican to see if a meeting, an audience with the Pope can be accommodated. We'll have further details on that. Obviously, we would be honoured to have an audience with his holiness."
Every U.S. president since Dwight D. Eisenhower has visited the Vatican to meet the pope. Eisenhower met St. John XXIII at the Vatican in December 1959.
But Woodrow Wilson was the first sitting U.S. president to meet a pope at the Vatican. He met with Pope Benedict XV in 1919 while on a European tour after World War I.
The visits are a mix of policy discussions and protocol, very civil and even warm affairs where, however, serious policy differences are raised. Depending on the president, his party and policies, the divergences run from issues related to the sacredness of the unborn to the obligation to care for creation and to welcome refugees