VATICAN CITY • Pope Francis urged Mr Donald Trump to use his US presidency to promote peace around the world, as the two leaders swopped sparring for smiles in their first face-to-face meeting at the Vatican yesterday.

Mr Trump's audience with the 80-year-old Pontiff, a keenly anticipated highlight of his first overseas tour, lasted just under half an hour and concluded with both men beaming, for the cameras at least.

"He is something," the President later said of his host. "We had a fantastic meeting."

The audience took place in the private library of the Apostolic Palace, the lavish papal residence that Pope Francis does not use, having opted instead for modest lodgings in a guesthouse for visiting clerics.

Pope Francis smiled faintly as he greeted Mr Trump outside the study and was not as outgoing as he sometimes is with visiting heads of state. Mr Trump, seeming subdued, said: "It is a great honour."

Even when the two were sitting at the Pope's desk in the presence of photographers and reporters, the Pope avoided the small talk that usually occurs before the media is ushered out. The two talked privately for about 30 minutes with translators. Both men looked far more relaxed at the end of the private meeting, with the Pope smiling and joking with Mr Trump and his wife Melania.

Pope Francis referred to Mr Trump's imposing bulk by asking Mrs Trump: "What do you feed him on? Potica?" - a reference to a calorie-laden cake from Slovenia, her country of birth.

Reporters in the room thought initially that the First Lady had replied "Pizza!" But her staff confirmed later that she had appreciated Pope Francis had produced a custom- made joke for her benefit.

Pope Francis then gave the President a small sculptured olive tree and told him through the interpreter that it symbolised peace.

"It is my desire that you become an olive tree to construct peace," the Pope said in Spanish. Mr Trump responded: "We can use peace."

Pope Francis also gave Mr Trump a signed copy of his 2017 peace message, whose title is "Non-violence - A Style Of Politics For Peace", and a copy of his 2015 encyclical on the need to protect the environment from the effects of climate change.

"Well, I will be reading them," Mr Trump said. He gave the Pope a boxed set of five first-edition books by murdered US civil rights leader Martin Luther King and a bronze sculpture.

In the past year, Pope Francis and Mr Trump have swopped jibes and debated on subjects ranging from migration to unbridled capitalism, as well as the environment. Their spats include the Pope describing plans for a border wall with Mexico as not Christian, and Mr Trump evoking a possible Islamist attack on the Vatican that would make the Pontiff glad to have him as President.

Afterwards, the Trumps were given a private tour of the Sistine Chapel and St Peter's Basilica.

The President then called on Italy's President Sergio Mattarella and met Prime Minister Paolo Gentiloni briefly. "We are loving Italy very much," Mr Trump said at that stop. "It was an honour to meet the Pope.

He later tweeted: "Honour of a lifetime to meet His Holiness Pope Francis. I leave the Vatican more determined than ever to pursue peace in our world."

Mr Trump's Vatican visit was the third leg of his overseas trip, after stops in Saudi Arabia, Israel and the Palestinian territories.

AGENCE FRANCE-PRESSE, REUTERS