President Donald Trump has said the decision to appoint a special counsel to oversee the inquiry into Russian influence on his election is hurting America terribly.
Speaking at a news conference in Washington, he denied any collusion with Russia during his election campaign last year.
“The entire thing has been a witch hunt and there is no collusion,” he said.
Former FBI chief Robert Mueller has been selected to lead the inquiry.
Mr Mueller’s appointment was welcomed by politicians from both sides. Mueller ‘is ramrod straight in integrity’
Calls for a special investigation had mounted after Mr Trump fired FBI Director James Comey last week.
On Thursday, Mr Trump denied trying to influence the investigation by sacking Mr Comey.
“Director Comey was very unpopular with most people,” he suggested.
“I actually thought when I made that decision… that it would be a bipartisan decision because you look at all of the people on the Democratic side, not only the Republican side, that were saying such terrible things about Director Comey.”
On Wednesday, Mr Trump had said no politician in history “has been treated worse or more unfairly” than himself.