PRINCE William will be tight-lipped with Donald Trump but the President-elect loves royals, an expert has said.
William will meet Trump at the re-opening of Notre Dame in Paris today.
The Paris cathedral has been restored after a fire tore through the roof in 2019 and destroyed much of the site's heritage.
William is expected to discuss the importance of the US-UK's 'special relationship' with Trump, Kensington Palace has announced.
The 42-year-old will also meet with outgoing First Lady Jill Biden, as will Trump.
Royal expert Hugo Vickers told The Sun: "I think the apolitical, soft diplomacy of the royal family is incredible.
"The late Queen was very good at that sort of thing, opening the way diplomatically.
"William knows that, so he will be there to to be friendly, and, you know, sort of, as it were open the path.
"Then the politicians can come in later, and they can do whatever they have to do."
He added: "That's the the wonderful role that the royal family performs so well."
Hugo said that Republican President-elect Trump reveres the royal family.
He said: "We know that President Trump was terribly keen to come over and meet the late Queen.
"And indeed he came twice he came to Windsor, and then he came on a state visit.
"Obviously she was an incredible icon to the whole world. It's amazing when you think.
"Trump's a powerful man as President of the United States. And yet he couldn't wait to come to meet her.
"He came away, has told several people that he was her favorite president.
"I've always thought that actually that was rather clever of the Queen.
"Because I bet you she made all the Presidents feel that they were her favourites, and she had that particular skill."
But Hugo said Prince William will have to be tight-lipped when speaking to Trump.
The expert said William will follow the late Queen's example when it comes to handling controversial world leaders.
He said: "This time Prince William is coming over to represent Britain at the reopening of Notre Dame,
"I'm sure Prince William will handle it very well, because, after all, he knows that Trump is the elected man.
"He will be leader of the Western world and US President as of January, and so they will obviously need to work with him.
"The late Queen was once being advised not to meet a particular political figure, I don't know which one it was.
"But she said, I didn't see why you advised me not to, because I meet mass murderers every day of my life.
"She had President Amin to lunch she met Makarios. She had Mobutu. Ceausescu came on a State visit.
"You know they are sent by the government, or they come for those reasons.
"The monarch, or in this case the Prince of Wales, has to handle it as best as he can, and they're very good at it. They do as they're bidden.
"And I suppose in some ways it makes it easier that they aren't there to discuss politics.
"Because Trump is going to be not only the head of state, but also the head of politics, if I can put it like this
"So in that respect I guess it makes it easier for Prince William. He, like the late Queen, will have to suppress any personal views that he has.
"Again I can tell you that the Queen, sometimes, when presented with a problem, would ask her private secretary, what should the Queen do?
"Not? What should I do? But what is the correct thing that the Queen should do under these circumstances.
"Then she listened to the advice, and then she took it."
The trip to Paris marks William's first visit since 2017 and will be his first meeting with Trump since his state visit to the UK in 2019.
The president-elect, making his first foreign trip since his election win, arrived at Orly airport in the south of Paris aboard a private plane just before 7am, a source told AFP.
William's discussion about the US-UK alliance comes as Trump has touted a more isolationist foreign policy and pledged to slap tariffs on trade.
Trump is also set to hold talks with Macron before the ceremony and may also meet Ukrainian leader Volodymyr Zelensky.
With dozens of guests present, Notre Dame's reopening will include the ritualised opening of the cathedral's massive doors, the reawakening of its organ and the celebration of the first Mass.
Macron toured the fully restored church last week as cameras were allowed in for the first time after the rebuilding project.
The extensive restoration took more than 60 months and cost a whopping £600million.
Work has included the total reconstruction of the collapsed fan-vaulted roof and spire, while builders unearthed previously unseen treasures from the smoking ruin.
Some 1200 oaks from across France were needed to completely rebuild the framework of the nave and the choir.
