President Trump denied knowing about a May 2019 letter from his personal attorney Rudy Giuliani requesting a private meeting with Ukrainian President Volodymyr Zelensky, despite Giuliani claiming that he was reaching out with Trump's "knowledge and consent."Why it matters: The letter, released by the House Intelligence Committee Tuesday, says that Giuliani was acting at the express direction of the president when carrying out a campaign to pressure Ukraine to investigate the Bidens."I don't know anything about the letter, but certainly Rudy is one of the great crimefighters in the history of our country," Trump said. "I didn't know about the specific letter, but if he wrote a letter it wouldn't have been a big deal."The big picture: Lev Parnas, a Giuliani associate who has been indicted on campaign finance charges, alleged in an explosive MSNBC interview Wednesday that Trump was fully aware of and authorized Giuliani's efforts in Ukraine.Trump told reporters that he does not know Parnas, suggesting he was simply one of the thousands of people with whom he's taken pictures at fundraisers.Parnas claimed on MSNBC that Trump is lying about not knowing him and that while he wouldn't consider them "friends," he and the president interacted on numerous occasions at roundtables and fundraising events.What to watch: Parnas said Wednesday that not all of the records he intends to hand over to the House Intelligence Committee have been released yet. He has signaled that he wants to testify in the impeachment trial, but it's not clear whether the Senate will vote to call him as a witness — especially given that he is under indictment and may not be a reliable narrator.Read the letter: Go deeper ... Lev Parnas: "Trump knew exactly what was going on" in Ukraine