Cohen's claims contradict statements from the president, Trump Jr. and their legal teams that Trump did not know about the Trump Tower meeting where Russians were expected to offer dirt on his then-Democratic challenger Hillary ClintonHillary Diane Rodham ClintonEx-NFL player accuses Trump of attacking "black culture" Pompeo spars with senators at testy hearing Budowsky: In 2018, women say no to Trump MORE until The New York Times reported on its existence past year. Cohen is willing to make that assertion to special counsel Robert Mueller, the sources said.
In short, if Cohen is determined to be telling the truth and Trump had been briefed about the Russians' offer of help before Trump Jr. convened the June 2016 meeting, it could mean Trump knew then that Russia was listening and that he expected it to act as it did.
At first, Trump Jr. said he never told his father of the meeting then later told Senate investigators that he couldn't recall who he spoke with that night.
Mr Weisselberg, who has worked closely with the Trump Organisation for decades, is considered a witness in the probe of Mr Cohen, The Wall Street Journal reported.
"Cohen is not a, you know, a heroic figure, but he does have credibility", Rep. Gerry Connolly, D-Virginia, told CNN's Jim Sciutto on "The Situation Room".
Mark Cuban, the billionaire businessman who was spotted dining with Cohen a couple of times in New York City a year ago, told CNN that Cohen has mostly talked to him about his hopes of writing a book and about his son's baseball career.
Cohen "even retained Bill and Crooked Hillary's lawyer", Trump tweeted.
On Friday, Trump lashed out at Cohen without naming him, saying on Twitter: "Sounds to me like someone is trying to make up stories in order to get himself out of an unrelated jam (Taxi cabs maybe?)".
About a month before Michael Cohen released his recording of a sensitive conversation he had with Donald Trump, the President's longtime attorney and adviser was agonizing over the silent treatment he was getting from his former boss.
Whether or not President Trump knew about his son's meeting with Russians is one of the central unanswered questions in a wide-ranging investigation into possible Russian collusion in the 2016 presidential election. The exchange makes it very clear that he was expecting to receive damaging information about Clinton as part of the Russian government's support for Trump as a candidate.
Trump has consistently denied that he knew about the meeting, and he did so again on Friday. The sources said Cohen does not have any evidence, including tapes, to back up his claims.
In response to Giuliani's claims this weekend that Cohen had violated the privilege, Cohen's attorney Lanny Davis issued a statement calling Giuliani "confused".
In the tape, the two men discuss how to buy the rights to a former Playboy model's story of her affair with Trump. They also note that two days before the meeting, Trump mysteriously announced plans to give a "major speech" about Clinton's scandals.
Mueller, who has led the Justice Department's probe into Russian meddling, is also looking into any links between the Russians and the Trump presidential campaign.The probe is also scrutinizing whether Trump sought to obstruct justice by firing Federal Bureau of Investigation director James Comey in 2017 and otherwise undermining other Justice Department officials.
Echoing his previous complaints, the President called Robert Mueller's investigation a "rigged witch hunt" under the control of "13 angry Democrats".