President Donald Trump has denied a bombshell report that he once ordered the firing of the special counsel leading the investigation into his campaign's ties to Russia, calling the report "fake news."

The New York Times on Thursday reported that Trump ordered Robert Mueller to be fired last June, one month after Mueller's appointed as special counsel. Trump fired FBI Director James Comey, who had been leading the Russia investigation, in May.

The Times said the White House counsel Don McGahn refused to direct the Justice Department to fire Mueller — and threatened to resign — and Trump was said to have eventually backed down from the decision.

"Fake news, folks, fake news," Trump told reporters in Davos, Switzerland, on Friday, where he is expected to give a speech at the World Economic Forum.