Seven charges in a previous indictment against Mr Manafort were reduced to just two in documents submitted to the court Friday by Special Counsel Robert Mueller, signaling a deal had been agreed with Mr Manafort's lawyers to accept guilt.
When the Eastern Virginia jury found him guilty in August, that conviction carried with it a maximum 80-year prison sentence.
In-person jury selection for his Washington trial was set to start Monday, with opening statements scheduled for September 24 before U.S. District Judge Amy Berman Jackson. The guilty plea today by Paul Manafort is a "big win" for Robert Mueller that should alarm Donald Trump.
Manafort, however, continues to hold a literal "Trump card", which he may elect to play only at the conclusion of court proceedings in his case.
The plea deal precludes the need for the second trial, sparing Manafort the steep legal fees of a second round of prosecution. Trump has denied colluding with the Russians and the Russians have denied interfering.
Manafort told the judge he wants to plead guilty.
"Usually, there would be some protection that if the government believes that the agreement was breached, that they can't use the statements that were made to the government during the period of cooperation with that person", the former prosecutor who spoke to Roll Call said.
Manafort is expected to appear in a US district courtroom in Washington, D.C., later Friday morning. According to NBC News, congressional investigators who are examining the meeting are "focused on determining whether it included any discussion of donations from Russian sources to either the Trump campaign or the Republican Party".
Several media outlets reported that Manafort is close to a plea deal with federal prosecutors.
Jurors in Virginia last month found Manafort guilty, in a separate case, on two counts of bank fraud, five counts of tax fraud and one charge of failing to disclose foreign bank accounts, giving special counsel Robert Mueller a victory in the first trial arising from his investigation of Russia's role in the 2016 USA election.
In their filing, prosecutors describe Manafort's scheme to take in more than $60 million from pro-Russian Ukrainians and launder that money to avoid paying taxes. But his involvement in key episodes under scrutiny, and his leadership of the campaign at a time when prosecutors say Russian intelligence was working to sway the election, may make him an especially valuable witness. They said "The President did nothing wrong and Paul Manafort will tell the truth"-taking out the truth part because that is very much the problem".
The decision by Trump's one-time personal lawyer Michael Cohen to plead guilty last month in a federal investigation in Manhattan particularly angered the president, who denounced him as a "flipper".
Under the terms of the deal, Manafort was allowed to plead guilty to just two counts, though the crimes he admitted largely overlap with the conduct alleged in an indictment past year.
It's unclear how the possible deal might affect Manafort's pursuit of a pardon from President Donald Trump.
The charges replace a raft of separate accusations that Manafort had failed to register as a foreign agent, lied to the government, laundered money and committed fraud.
"He's accepted responsibility", Manafort's lawyer Kevin Downing, said. "'Justice" took a 12 year old tax case, among other things, applied tremendous pressure on him and, unlike Michael Cohen, he refused to "break" - make up stories in order to get a "deal.' Such respect for a courageous man!"