He said he expected to be questioned by justice department special counsel Robert Mueller within two to three weeks, with approval from his lawyers.
“I would love to do that as soon as possible,” said Mr Trump.
The president had previously said he thought it “unlikely” he would be interviewed by Mr Mueller.
He has called the Russia investigation a “witch hunt” and a “hoax”.
Speaking at the White House on Wednesday, Mr Trump maintained he was “absolutely” prepared to be questioned under oath by the top investigator.
“There’s been no collusion whatsoever, there’s no obstruction whatsoever,” he said.
The US intelligence community has already concluded that Moscow tried to sway the presidential election in favour of Mr Trump, though Russia denies that.
The president’s lawyers have been talking to Mr Mueller’s team about an interview, and the form it might take.
The questioning could happen face-to-face, in writing, or it could be a combination of both.
As to when it might happen, Mr Trump said: “Yesterday they were talking about two to three weeks.”
Asked if he thought Mr Mueller would be fair, the president replied: “We are going to find out… I hope so.”
Mr Trump told reporters that his former rival Hillary Clinton was not prepared to be interviewed under oath by the FBI about her use of a private email server.
The Republican president also said he did not recall asking an acting FBI director about his voting record.
“I don’t think I did,” he said. “I don’t know what’s the big deal with that.”
Andrew McCabe, who took over the FBI after the president fired its previous director, James Comey, last May, said he found Mr Trump’s Oval Office question “disturbing”.
Mr McCabe said he told the president that he did not vote in the 2016 presidential election, according to the Washington Post.
Mr Mueller is thought to be investigating whether Mr Comey’s firing was an attempt to obstruct justice.
The country’s top prosecutor is thought to be the first member of the Trump cabinet to be questioned. (Courtesy BBC)