Yet despite that, he did not appear very comfortable. Inside New York’s Trump Tower, he scowled and frowned, and hissed his defiance. He was furious with the intelligence services, which he claimed had been behind the leak of unverified claims about compromising sexual and business behaviour in Russia.

“It was a disgrace that the information was let out. I read the information, it was fake news, it’s phony news,” he said. “Sick people put that c**p together.”

It had been 168 days since Mr Trump last held a news conference and there was lots to talk about on Wednesday morning. The event had long been scheduled for the President-elect to explain how he was going to erect a legal barrier between his work heading the country, and his work heading the Trump business empire.

Yet his plans were hijacked overnight by the publication of revelations that US intelligence officials had briefed him and President Barack Obama that Russia had obtained compromising personal and financial information about him. The officials had reportedly told Mr Trump that agents had been seeking to use the information - collected originally as “political oppo” by a former British spy in the pay of Mr Trump’s presidential rivals - as leverage against him.

“I saw the information, I read the information outside of that meeting,” Mr Trump said. “It’s all fake news, it’s phony stuff, it didn’t happen. It was gotten by opponents of ours.”

Several hours before the news conference, Mr Trump had been defending himself on Twitter, blasting the actions of the intelligence agencies, and likening their alleged leaking of the information to what went on in Nazi Germany.

“Russia just said the unverified report paid for by political opponents is “A COMPLETE AND TOTAL FABRICATION, UTTER NONSENSE”. Very unfair!,” wrote Mr Trump, on this occasion mixing up his use of capital letters.

Russia had earlier also denied claims that its intelligence agencies have compromising material about Mr Trump.

Dmitry Peskov, President Vladimir Putin’s spokesman, said the allegations were “pulp fiction” and a “clear attempt to damage relations”, the BBC said.

Mr Trump has repeatedly refused to accept that Russian agents had hacked the Democratic National Committee during the election in order to help his candidacy. The revelation led Mr Obama to expel 35 Russian diplomats.

Mr Trump, by turn, has been accused of being too friendly to Mr Putin. On Wednesday, the New York tycoon told reporters that if he improved America’s “horrible relationship with Russia”, it would be a good thing.

Donald Trump: Putin liking Trump is an asset not a liability

“If Putin likes Donald Trump, guess what, folks, that’s called an asset not a liability. I don’t know if I’m going to get along with Vladimir Putin - I hope I do - but there’s a good chance I won’t,” he said.

In regard to his promise to ensure there would be no conflict of interest once he becomes president, Mr Trump introduced lawyer Sheri Dillon, of Morgan Lewis, who worked with the Trump Organisation on a new arrangement.

Ms Dillon said the Trump Organisation would continue to pursue deals in the US, though Mr Trump will relinquish control of the company to his sons and an executive, put his business assets in a trust and take other steps to isolate himself from his business.