Transcript for Rudy Giuliani says Trump never instructed his former lawyer to lie to Congress

president trump's personal lawyer, Rudy Giuliani, fighting back against the disputed buzzfeed report that alleged president trump instructed Michael Cohen to lie to congress about a trump tower project in Moscow. David Wright is at the white house. Reporter: Today, the president's lawyer insisted his client never ordered his previous lawyer to lie to congress about negotiations to develop a trump tower in Moscow. Categorically, I can tell you his counsel to Michael Cohen throughout that entire period was, "Tell the truth." Reporter: That issue is at the heart of a disputed report by buzzfeed news that claimed the special counsel has evidence president trump personally directed Michael Cohen to lie to congress. The special counsel's office made a rare public denial of the buzzfeed report. The white house disputes it as well. Today, Rudy Giuliani left open the possibility that trump may have spoken to Cohen about his testimony. But said trump didn't even hint Cohen should lie. It's not possible. Not possible. Michael Cohen left the conversation thinking, well, this is what the boss wants me to say. The boss wants me to say -- Not possible. Reporter: Cohen told congress negotiations over trump tower Moscow ended in January, 2016, before the 2016 presidential primaries. But later admitted that was a lie. In his guilty plea, Cohen said the negotiations over the Moscow property continued as late as June, 2016, when trump was the presumptive GOP nominee. Giuliani has even suggested negotiations may have gone on even longer. According to the answer that he gave, it would have covered all the way up to November of 2016. Reporter: Democrats plan to question Cohen next month about his false testimony and about what instructions, if any, he had from his client. If anyone was instructing, whether it was the president or other people affiliated with the white house, or the trump organization, encouraging a witness to lie, we need to know about it. Reporter: Lawmakers will hear from Cohen February 7th, when he will appear before the house oversight committee. The senate may also want to bring him in for questioning. After that, Cohen heads to prison. A three-year sentence for this and other charges. Tom? David, thank you. Next to the viral video shot

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