Cohen pleaded guilty on Thursday to lying to Congress about the project, putting fresh pressure on the president.
Cohen began talking to investigators working for Special Counsel Robert Mueller, whose probe has been a thorn in Trump's side, after pleading guilty in August to bank fraud and campaign finance violations in NY.
Russian President Vladimir Putin's spokesman said in August 2017 that he had received an email in January 2016 from Cohen about a Moscow real estate project, but said he had neither replied nor discussed it with Putin.
Trump called Cohen a "weak person" who is lying to get a lighter sentence. Now he says that they in fact continued until June of that year, by which point Trump had effectively won the Republican nomination for the presidency.
"I made these mis-statements to be consistent with individual 1's [Trump's] political messaging and out of loyalty to individual 1", Mr Cohen said in court.
Oh, and as journalists are noting, if Cohen is guilty of lying to Congress, that means Don Jr.is too.
The comment came the same day Cohen pleaded guilty in special counsel Robert Mueller's Russian Federation investigation.
Cohen admitted misleading lawmakers on talks during the presidential race about a Trump property deal in Moscow.
Another former federal prosecutor, Harry Sandick, pointed out that getting these damning details out in the open allows Mueller to keep the public appraised of some of what his investigation has turned up.More news: Google Pixel 3 Lite leaks once again, poses for the camera
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Cohen's lawyer told the judge the plea deal involved cooperation with Mueller's investigation of Russian interference in the US election.
"There would be nothing wrong if I did do it", he said.
Mueller's probe has yielded a mountain of evidence against Manafort, who was convicted of eight criminal charges (including bank and tax fraud) on August 22 and was facing a second trial for charges ranging from money laundering to obstruction of justice.
"He was convicted with a fairly long-term sentence with things unrelated to the Trump Organization", Trump said, citing Cohen's legal issues with mortgages and the IRS.
The filing comes days after Trump submitted his written responses to Mueller's questions about his involvement with Russian Federation as a presidential candidate. Prosecutors claim that Cohen's lie was a way to distance Trump from any business dealings in Russian Federation.
Cohen admitted he violated 18 USC § 1001 (a)(2), which makes "any materially false, fictitious, or fraudulent statement or representation" a federal crime.
Mr Trump told reporters of the Moscow real estate project, which never came to fruition: "When I'm running for president that doesn't mean I'm not allowed to do business".
Senate Intelligence Committee chairman Richard Burr says Cohen's guilty plea shows "the reason people shouldn't lie when they're in front of a congressional investigation".
"You know this flipping stuff is awful", Trump, who has repeatedly called for Mueller's "witch hunt" led by "angry Democrats" to come to an end, told the Post. Cohen is scheduled to be sentenced December 12.