US president Donald Trump has again turned to Twitter to flaunt his own stature, this time bragging about his supposed supreme intelligence.

Coinciding with Michael Wolff's book Fire and Fury: Inside the Trump White House, which has questioned Trump's ability to run the country – to put it mildly – Trump tweeted to remind everyone that he was "really smart". In true Trump fashion, he labelled Wolff as a "total loser".

"Now that Russian collusion, after one year of intense study, has proven to be a total hoax on the American public, the Democrats and their lapdogs, the Fake News Mainstream Media, are taking out the old Ronald Reagan playbook and screaming mental instability and intelligence," Trump tweeted.

"Actually, throughout my life, my two greatest assets have been mental stability and being, like, really smart. Crooked Hillary Clinton also played these cards very hard and, as everyone knows, went down in flames. I went from VERY successful businessman, to top T.V. star. to President of the United States (on my first try)."

Trump concluded his social media rant and said: "I think that would qualify as not smart, but genius... and a very stable genius at that!"

Some of the insights from Wolff's book include Melania Trump allegedly crying on election night from sadness, the Trump election team being shocked and horrified about his win and employees in the White House telling the author his 'mental powers were slipping'."

Earlier in January, Trump's lawyers attempted to stop the release of the book. Former staff member Steve Bannon also claimed that Trump's son, Donald Trump Jr, had met with Russians to dig up dirt on Hilary Clinton during the 2016 campaign.

The president reacted angrily to the revelations on Wednesday afternoon (3 January) claiming that "Steve Bannon has nothing to do with me or my presidency. When he was fired, he not only lost his job, he lost his mind," Trump said.

"Steve was a staffer who worked for me after I had already won the nomination by defeating seventeen candidates, often described as the most talented field ever assembled in the Republican party."

Bannon was fired by Trump in August 2017, and went on to return to his former right-wing website, Breitbart.

Fire and Fury: Inside the Trump White House will be released on 9 January. If you want to know how to buy it, click here.