US President Donald Trump took credit for Saudi Arabia's political shakeup which resulted in the elevation of Mohammed bin Salman to the position of crown prince last year, according to a startling account of his administration's first year in the White House.

The suggested claim is included in Fire and Fury: Inside the Trump White House, a controversial new book by Michael Wolff which reveals, among others, the US president's close connections to Saudi Arabia.

"We've put our man on top," Trump is said to have claimed to friends, according to the book, after Saudi King Salman removed his nephew Crown Prince Mohammed bin Nayef as next-in-line to the throne and replaced him with his son, Mohammed bin Salman, in June 2017.

The move marked a departure from Saudi Arabia’s line of succession, breaking with decades of custom maintained by the Kingdom’s royal family.

The veracity of the book's claims has been contested by Trump, who said on Friday Wolff's book is "full of lies”.

I authorized Zero access to White House (actually turned him down many times) for author of phony book! I never spoke to him for book. Full of lies, misrepresentations and sources that don’t exist. Look at this guy’s past and watch what happens to him and Sloppy Steve! — Donald J. Trump (@realDonaldTrump) January 5, 2018

Trump visited Saudi Arabia's capital, Riyadh, in May 2017 at the beginning of his first overseas tour as US president, having hosted Mohammed bin Salman in Washington, DC, two months earlier.

Mohammed Cherkaoui, a professor of conflict resolution at George Mason University, told Al Jazeera the account provided by Wolff in his book was "well-researched".

"This is based on scores of interviews with people inside the White House and around Trump," he said.

"It explains to some extent how Trump managed to influence the decision of King Salman … [and] goes back to the period when Mohammed bin Salman visited the US in March and the Riyadh summit which Trump attended in May [when] apparently he was lobbying ... [for] a powerful man," added Cherkaoui.

"[Trump] was basically grooming Mohammed bin Salman."

The US president has been openly supportive of the Saudi crown prince in recent months, notably praising him after the dismissals and arrests of a number of senior ministers, businessmen and princes as part of an alleged anti-graft campaign.

"I have great confidence in King Salman and the Crown Prince of Saudi Arabia, they know exactly what they are doing," Trump said on Twitter two days after the anti-corruption crackdown began on November 4.

Cherkaoui said Trump's backing of the Saudi crown prince is a reflection of the US president's "political philosophy".

"He wants to deal with individuals, not institutions and not governments, so it's a one-to-one," he said.

"Trump saw in Mohammed bin Salman somebody who has the right influence, and also someone who would put the Saudi-US relationship into a higher dimension, both in an economic and strategic way [and help] combat terrorism which has become the new currency of Trumpism."