Donald Trump, master of the mixed message, has experienced confused feelings of admiration, disapproval, and, even, an intimate sense of identification, towards Pope Francis, 226th sovereign of Vatican City. And where better to publish his mercurial grapplings than Twitter? Back in 2013, when the notoriously modest Argentinian Jesuit was elected, Trump was upbeat. “People that know him love him!” he typed, brightly, suggesting an exclusive level of celestial insight. But, just five days later, it was this modesty that tainted his effulgent view of the pontiff. “I don’t like seeing the Pope standing at the checkout counter (front desk) of a hotel in order to pay his bill. It’s not Pope-like!” reprimanded the proprietor of Trump Towers. His misgivings were short-lived. By December that year, Trump had developed a sneaking suspicion that—although he would never be caught near any checkout counter—the duo shared the same sort of chaste aura. “The new Pope is a humble man, very much like me, which probably explains why I like him so much!”

Wednesday morning, on the third leg of his first foreign trip as president, Trump met with the pope at the Apostolic Palace. Despite only deciding to visit shortly before, a trip to the Vatican seemed the natural way to conclude his whistle-stop tour of world religions, during which he had already called for a collective fight against terror while securing a $110 billion arms deal with Saudi Arabia, and wrapped-up a visit to Israel by sagely asserting that both Israelis and Palestinian leaders “are ready to reach for peace.”

Exhausted by his endeavors, this was to be Trump’s most challenging meeting yet. The president and the pope possess bluntly antithetical slants on issues such as immigration and climate change. Francis has berated Trump’s anti-Muslim rhetoric, and denounced his pledge to build a wall across the Mexican border. “A person who thinks only about building walls, wherever they might be, and not building bridges, is not Christian,” he said.

Trump, who appeared to have retained his belief in his divine credentials, but conveniently lost the papal part, hit back, saying it was “disgraceful” of the pope to question his faith. “If and when the Vatican is attacked by ISIS, which as everyone knows is ISIS’ ultimate trophy, I can promise you that the pope would have only wished and prayed that Donald Trump would have been president,” he declared, during his election campaign.

But, if Trump’s touchdown in Riyadh was accompanied by a macabre fanfair of celebration, with billboards round the city thumping with flashing snippets of his tweets, his reception in Rome was a less cinematic but still cordial affair. Accompanied by an entourage of aides and advisors, he arrived at the palace in a limousine. Shortly after, the pope pulled up in a blue Ford Focus, in time for their 8:30 A.M meeting, squeezed in before his weekly, 10 A.M address.

Greeted by Archbishop Georg Ganswein, the prefect of the pontifical household, Trump entered a small elevator taking him to the third floor of the Palace and, after a ceremonial walk past frescoed corridors, shook the pope’s hand at the entrance to his private study.

Perhaps the most nervous person present was the translator, charged with mediating between the pair for precisely 29 minutes. “It is my desire that you become an olive tree to construct peace,” the pope apparently said, via the interpreter, gifting the president as small sculpted version of said tree. Trump responded: “We can use peace.” Francis also gave Trump a signed copy of his 2017 peace message whose title is “Nonviolence — A Style of Politics for Peace,” and a copy of his 2015 encyclical letter on the need to protect the environment from the effects of climate change. “Well, I’ll be reading them,” Trump said.

It wasn’t the first time the pope has seemed to offer oblique criticism of the president:

After their tête-à-tête, the pair were joined by others, including Melania and Ivanka Trump, and Jared Kusher. Francis apparently asked the Slovenian First Lady if she fed her her husband potica, a popular type of cake. There was a pause. Melania might have been living in the States too long. “Pizza?” she replied. “Yes.” A press spokesperson for the Vatican commented that the pope personally loves potica, and tends to mention it whenever he meets a Slovenian.

Beyond the pageantry, and the photographs, and the cultural culinary jokes, the meeting of the two leaders is significant. But, with their utterly different understandings on how to tackle global problems, it might not move beyond symbolism. Speaking on the papal plane after a recent trip to Portugal, Francis was lucid about what he would say to Trump. “In our talk things will come out, I will say what I think, he will say what he thinks, but I never, ever, wanted to make a judgement without hearing the person.”

Trump leaves Rome later today, and flies to Brussels for a NATO meeting Thursday. In the wake of Monday’s terror attack in Manchester, which killed 22, and recent atrocities across Berlin, London, Nice, Brussels, Stockholm and Paris, the summit will be under sharp scrutiny. It remains to see how the pope’s measured message of peace will play out.