The hearing came a day after Trump's former personal attorney Michael Cohen pleaded guilty to a charge of lying to Congress about plans to build a Trump Tower in Moscow. Cohen, who has already reportedly spent dozens of hours in interviews with Mueller's team, agreed to cooperate with the special counsel as part of his plea deal.
Mueller is investigating Russian interference in the 2016 U.S. presidential election, possible coordination between Russia and Trump campaign-related people, and potential obstruction of justice by the president himself.
On Monday, Mueller's team alleged in a court filing that Manafort had lied about "a variety of subject matters" to the FBI after entering into his own plea agreement with the special counsel in September. Mueller said the breach of terms relieves the special counsel from its obligations to the plea agreement, but maintains all of Manafort's duties.
Manafort's lawyers pushed back on the allegation, made in a joint document sent to Jackson in the D.C. court. Manafort "believes he has provided truthful information and does not agree with the government's characterization or that he has breached the agreement," the lawyers said.
The special counsel had lodged charges against Manafort in D.C. and a federal court in Alexandria, which mostly related to work he did for a pro-Russia political party in Ukraine years before he became Trump's campaign chief in early 2016. Manafort was convicted of eight criminal counts in the Virginia case in August, and struck a deal with Mueller on the eve of his second trial in D.C.
His sentencing in the Virginia case is set for Feb. 8.
In June 2016, Manafort, along with Donald Trump Jr., and Trump's son-in-law Jared Kushner, met a Russian lawyer at New York's Trump Tower in hopes of receiving damaging information about Trump's then-political opponent, Hillary Clinton. In a letter to Mueller's team in January, the president's legal team said that Trump himself had "dictated" a response to The New York Times' story about the Trump Tower meeting.
Cohen on Thursday admitted that he had lied when he told the Senate Intelligence Committee in a letter that the proposal for a Moscow Trump Tower "ended in January 2016 and was not discussed extensively with others" in the Trump Organization.
Rather, Cohen knew that the Moscow project had been discussed as late as about June 2016, Mueller said in a criminal information filing. Cohen also briefed Trump about the project on more occasions than he claimed to the Senate committee, and had "briefed family members of [Trump] within the Company about the project."