VATICAN CITY, AP, 23 May 2017 — President Donald Trump and Pope Francis share a trait that adds drama to their first meeting Wednesday: unpredictability. And when they greet each other — in a Vatican ceremony laden with history and symbolism — they may well find common ground, particularly in denouncing religiously inspired violence and demanding Muslim leaders take a greater stand in rooting out fanaticism from their places of worship.

President Donald Trump has arrived in Rome for a visit with Pope Francis. The stop is the third on Trump first foreign trip and follows visits to Saudi Arabia and Israel. (May 23)

To reach public harmony, the two men, unquestionably two of the most famous figures on the planet, will have to set aside their past and very public conflicts.

When Trump took his oath of office on Jan. 20, Francis sent him a telegram of congratulations, offering his prayers for wisdom and strength that the new president’s decisions would be guided by ethical values.

“Under your leadership, may America’s stature continue to be measured above all by its concern for the poor, the outcast and those in need, who, like Lazarus, stand before our door,” the message read.

Trump’s visit to the Vatican is the third leg of his tour of the world’s three main monotheistic religions, coming after he visited the cradles of Islam and Judaism. While pope and president differ on many social and economic issues, the two are preaching from the same playbook in demanding that Muslim leaders take a greater stand against extremists in their mosques and communities. It’s likely that both sides will seek to highlight such common ground after their Wednesday morning audience.

Police are performing security operations ahead of a private audience between President Donald Trump and Pope Francis scheduled for Wednesday at the Vatican.

In Saudi Arabia on Sunday, Trump implored Middle Eastern leaders to extinguish Islamic extremism from the region and described it as a “battle between good and evil” rather than a clash between the West and Islam. Those words echoed what Francis said in a trip to Egypt last month as the pope demanded the country’s imams teach their young to reject the use of violence in God’s name and backed an Egyptian government crackdown on Islamic militants who have increasingly targeted the country’s Christian community.

“As religious leaders, we are called to unmask violence that masquerades as purported sanctity,” Francis said April 28 at Cairo’s Al-Azhar, the revered, 1,000-year-old seat of Sunni Islam learning that trains clerics and scholars from around the world.

Last week, the pope said he’d “never make a judgment about a person without hearing him out” when asked about the president.

“I think they may be a little less different than we think,” said Joseph Capizzi, a professor of moral theology at the Catholic University of America. “While the pope emphasizes humility, he, like Trump, is a savvy media personality. He and Trump both are effective at using the media. Instead, I think their agendas really don’t converge much, and thus I don’t see much opportunity for working partnership.”

An Italian Police bomb disposal expert walks in a cordoned-off an area of Viale della Conciliazione avenue leading to St. Peter’s Square. Police are performing security operations ahead of a private audience between President Donald Trump and Pope Francis scheduled for Wednesday.

Papal visits with heads of state are carefully arranged bits of political and religious theater that follow a specific program, with little room for deviation or unwanted surprises. Trump will be given a tour of the Vatican after he arrives and will then first meet with the pontiff in his library. The two men will then be left alone with a translator to hold a private discussion before emerging again to exchange gifts and farewells. Trump will also view the Sistine Chapel.

Trump will be the 13th president to visit the Vatican. Francis got along exceedingly well with Barack Obama, and they had lengthy meetings both in Rome and Washington, as the former president praised the pope as a beacon of social justice. Other presidents and popes have also shared goals, including Ronald Reagan and Pope John Paull II who were united in their hopes for the defeat of communism.