The U.S. special counsel in the Russian election meddling investigation has learned of two conversations in which President Donald Trump asked witnesses about matters discussed with investigators, the New York Times reported on Wednesday.

The newspaper, which cited three unidentified people familiar with the matter, said Trump told an aide that White House counsel Donald McGahn should issue a statement denying a New York Times article in January that said McGahn told investigators the president had once asked him to fire special counsel Robert Mueller.

McGahn did not issue a statement and he "later had to remind the president that he had indeed asked Mr. McGahn to see that Mr. Mueller was dismissed," the Times report said.

Trump also asked his former chief of staff, Reince Priebus, how his interview with the special counsel investigators had gone and whether they had been "nice."

Mueller's investigation arose in part from the findings of U.S. intelligence agencies that Russia had meddled in the 2016 U.S. election and that its goals eventually included aiding Trump, who won a surprise victory over Democrat Hillary Clinton.

Russia denies the allegations and Trump says there was no collusion between Moscow and his campaign.

Mueller has charged several Trump associates and more than a dozen Russians.