But that was largely forgotten - or at least ignored - when Mr Trump swept up to St Peter's Square in a 50-car motorcade, to be met by Swiss Guards in traditional harlequin uniform.
One of the leading questions on people's mind is why Melania chose not to cover her head in Saudi Arabia, where women are supposed to cover up by law, and wore a veil while meeting the Pope in the Vatican?
Francis had a light moment with the first lady, asking via translator, "What do you give him to eat, potica?" referring to a favorite papal dessert from her native Slovenia.
Climate change activists projected the words "Planet Earth First" on the massive dome of St. Peter's Basilica at the Vatican Tuesday night and protests are expected after Trump arrives in Brussels for a North Atlantic Treaty Organisation meeting and Sicily for a G-7 gathering.
In one of the lighter moments of his meeting with the U.S. president at the Vatican on Wednesday, Francis made an apparent allusion to Trump's imposing physical size.
Mrs Trump placed flowers at the feet of a statue of the Virgin Mary and spent time praying at the Bambino Gesù Hospital during her visit.
Djokovic makes winning French Open start on Agassi's watch
The 35-year-old Ferrer prevailed 5-7, 6-3, 4-6, 6-3, 13-11 and improved to 22-11 in five-set matches (6-1 at French Open ). Philipp Kohlschreiber, (29) Juan Martin del Potro vs. countryman Guido Pella, and Nicolas Almagro vs.
Before the door of the wood-lined elevator closed, a Vatican protocol official was heard quipping to the President that it was not "like Trump Tower in New York".
Pope Francis shakes hands with Ivanka Trump on the occasion of a private audience, at the Vatican, Wednesday, May 24, 2017. Melania Trump asked if he said potica or pizza, then laughed and said yes.
Traveling as a couple can be stressful, and the first lady and her husband aren't immune to that, five-star hotels and Secret Service and all.
Trump will later meet Italian President Sergio Mattarella and Prime Minister Paolo Gentiloni.
As previously reported, in February 2016, Trump expressed offense when Bergoglio suggested that he was not a Christian because of his desire to build a border wall to keep out illegal immigrants. "A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian", The pope who is a strong advocate of helping refugees, particularly those from Syria, said it both a "moral imperative" and "Christian duty" to help them. In Saudi Arabia, he addressed dozens of Arab leaders and urged them to fight extremists at home and isolate Iran, which he depicted as a menace to the region.
While Trump received warm welcomes in Riyadh and Jerusalem, the reception could grow cooler now that he's reached Europe, site of widespread protests after his election.
Trump retorted that it was "disgraceful" for the pope to doubt his faith.