President Trump held a half-hour private meeting with Pope Francis at the Vatican on Wednesday, declaring it a “great honor” despite their past public dissension.

The unconventional Republican and the first Jesuit pontiff made for an unlikely pair in the Vatican’s Apostolic Palace, where Catholic leaders have presided or centuries and American presidents have come or decades.

Francis was silent as the two sat across one another at the pope’s wooden desk to begin the audience at approximately 8:30 a.m. local time. Exactly a half-hour later, the ringing of a bell signified the end of the private encounter.

For the White House, the Vatican stop caps a tour through key sites of the world’s three major religions, following stops in Saudi Arabia and Israel, designed to promote tolerance and a united approach to terrorism.

“When you put it all together, you’re really showing that this problem of radical extremism is one of the great problems of our time,” a senior Trump aide told reporters Tuesday en route from Israel to Rome, briefing anonymously as is common White House practice. “By putting everybody together you can really build a coalition and show that it’s not a Muslim problem, it’s not a Jewish problem, it’s not a Catholic problem, it’s not a Christian problem, it really is a world problem.”

In an exchange of gifts after their private meeting, Francis offered the president a medal by a Roman artist of an olive, a symbol of peace.

“We can use peace,” Trump responded.

Where Trump’s and Francis’ interests may align on peace and combating terrorism, they disagree sharply on issues like immigration and poverty.

Like Trump, the Argentine pope has shown a predilection for unscripted comments that have shaken the staid Vatican bureaucracy, as when he criticized candidate Trump’s proposed stricter immigration policies including a border wall as “not Christian.” Trump fired back, calling the pope’s remarks “disgraceful.”

Any animosity was not apparent Wednesday, as a meeting between Francis and a larger U.S. delegation ended.

“Thank you. I won’t forget what you said,” Trump said.