Washington(CNN) President Donald Trump continues to insist he doesn't know Lev Parnas, an associate of Trump's personal attorney who now says the President was aware of efforts to surface dirt on political rivals.

Speaking in the Oval Office, Trump said he didn't know anything about Parnas, with whom he's posed in photographs.

"I don't know him at all, don't know what he's about, don't know where he comes from, know nothing about him. I can only tell you this thing is a big hoax," he said, adding, "He's probably trying to make a deal for himself."

Parnas, the Soviet-born businessman whose work in Ukraine with Rudy Giuliani stands at the center of the impeachment inquiry, implicated the President in the Ukraine pressure campaign on Wednesday in an interview with CNN.

"Perhaps he's a fine man. Perhaps he's not," Trump said on Thursday, later adding, "I don't believe I've ever spoken to him."

Trump said he takes thousands of photos at fundraisers, but suggested that did not mean he knows Parnas.

"I don't need the help of a man that I never met before other than perhaps taking a picture at a fundraiser," he said.

But on Wednesday, Parnas told CNN's Anderson Cooper that the efforts in Ukraine were "all about 2020" and not about working in the interest of the United States.

"That was the way everyone viewed it," Parnas said, disputing Trump's previous claim that the push to unearth damaging information about his political rival, Democratic presidential candidate and former Vice President Joe Biden, stemmed from concerns about corruption in Ukraine.

"That was the most important thing," Parnas said, "for him to stay on for four years and keep the fight going. I mean, there was no other reason for doing it."

Parnas was indicted in October by New York federal prosecutors on campaign finance charges alongside another Giuliani associate, Igor Fruman. Parnas and Fruman have pleaded not guilty to the criminal charges.