Trump then approved a meeting taking place, CNN reported on Thursday night, citing sources with knowledge of the matter.
That would create another headache Trump's defense team.
U.S. President Donald Trump's ex-lawyer Michael Cohen has largely stayed out of the spotlight in the months since federal agents raided his office and hotel room and seized scores of records about his work for Mr. Trump.
The criticism Giuliani is now leveling at Cohen follows a series of reports that have led the President to lash out at his former lawyer.
"President Donald Trump on Friday denied his former personal attorney Michael Cohen's claim that he knew in advance about the June 2016 Trump Tower meeting in which Russians were expected to offer dirt on Hillary Clinton."(No, ) I did NOT know of the meeting with my son, Don jr".
The Trump Tower meeting was arranged by a music promoter, Rob Goldstone, who reached out to Trump Jr saying he had "official documents and information that would incriminate Hillary and her dealings with Russian Federation and would be very useful to your father".
Rep. Eric Swalwell, the top Democrat for the CIA on the House Permanent Select Committee on Intelligence, told CNN on Thursday: "Rudy Giuliani described him [Cohen] as a proven liar but all of his lies in the past were on behalf of Donald Trump".
Mark Cuban, the billionaire businessman who was spotted dining with Cohen a few times in New York City past year, told CNN that Cohen has mostly talked to him about his hopes of writing a book and about his son's baseball career.
The two sides have been negotiating all year, even after Trump changed legal teams and Mueller pursued indictments of Russian officials accused to seeking to interfere in the 2016 elections.
California fires: Thousands forced to flee as Carr fire spreads
Wildfires around the state have forced roughly 50,000 people from their homes , said Lynne Tolmachoff, a Cal Fire spokeswoman. Firefighters in Napa Valley also worked to contain the Steele fire which had burned 150 acres and destroyed 7 structures.
Spectrum Ordered to Leave New York
Unless overturned, this action will mean that Charter will no longer be permitted to operate in the state of NY . The commission had previously ordered Charter to pay a $2 million fine for its slow broadband rollout.
Iran plans to respond in kind if US blocks oil exports
Though Iranian President Hassan Rouhani said Wednesday there was no need for him to "respond to any nonsensical comment", Gen. Rouhani had warned his U.S. counterpart not to play with the lion's tail after Trump's push to halt Iran's export of oil.
'One of those is with the president of the United States.
Giuliani later added: "There's no doubt in my mind that he's just not credible". This is the kind of witness that can really destroy your whole case, because any finder of fact loses confidence in the case when you rely on a guy like this.
"Did he reference this meeting in particular when you talked to him?"
But in calling Cohen a liar, Giuliani may have created another legal problem for Trump - by effectively asserting that Cohen had been lying for Trump while still working for him.
One Republican source intimately involved in NY politics told CNN that it was Cohen who called him in 2013 to pass along the message that Trump was interested in running for governor.
Trump denied knowledge of the meeting in a tweet Friday morning. Giuliani claimed Sunday the recordings contained no evidence that implicated the president in illegal activity.
Trump's eldest son, Donald Trump Jr, along with Trump's son-in-law Jared Kushner and senior campaign aide Paul Manafort took part in the meeting with Nataliya Veselnitskaya, a Russian lawyer and acknowledged Kremlin informant.
Also as part of his tweet storm, Trump attacked Mueller and his prosecutors for examining past presidential tweets as part of an obstruction of justice investigation. The Times also reported in June that Trump personally dictated a misleading statement about the goal of the meeting, even after his aides repeatedly denied that he did so. At the time, the Russian operation to covertly boost Trump's candidacy wasn't publicly known.
Sources tell CNN numerous tapes include discussions with reporters and conversations relating to President Trump.