U.S. prosecutors on Friday agreed to drop criminal charges against Paul Manafort that a jury deadlocked on earlier this year, as a federal judge set a Feb. 8 date for Manafort's sentencing on charges of bank fraud and filing false tax returns.

Prosecutors had favoured waiting until the former Trump campaign chairman finished co-operating with special counsel Robert Mueller's probe into Russian interference in the 2016 election before addressing the remaining charges.

But U.S. District Judge T.S. Ellis rejected the timetable so he could move forward with sentencing Manafort, who appeared in court in a wheelchair and was said to be suffering significant health issues.

"I have not heard any estimation from the government of when his co-operation will be complete," Ellis said, referring to the special counsel investigation. "I'm not willing to go on endlessly" before sentencing Manafort, he added.

Ellis dropped the charges on which the jury had deadlocked, but did so without prejudice, meaning the prosecution could reintroduce them. He set a Feb. 8 sentencing date for the tax and bank fraud charges on which Manafort was convicted.

At his trial in August, Manafort was convicted on eight counts of bank fraud, tax fraud and failing to disclose foreign bank accounts.

But the jury was unable to reach a verdict on 10 other charges, including failure to register foreign bank accounts and conspiracy to commit bank fraud, so a mistrial was declared on those.

Kevin Downing, attorney for former Trump campaign chair Manafort, was at the courthouse in Alexandria, Va., for Friday's decision. (Alex Wong/Getty Images)

Ellis's decision to push ahead with sentencing on the eight convictions could result in Manafort receiving a higher prison sentence at first, which prosecutors could then seek to have reduced if he assists the Mueller probe.

Several sentencing experts predicted Manafort, a 69-year-old former political consultant, would receive a prison term of about 10 years.

Manafort is the most senior of President Donald Trump's former aides to be convicted in Mueller's Russia investigation.

Prosecutors accused him of hiding from U.S. tax authorities $16 million US he earned as a political consultant for pro-Russian politicians in Ukraine to fund an opulent lifestyle, and then lying to banks to secure $20 million in loans after his Ukrainian income dried up and he needed cash.

The charges largely predated Manafort's tenure on Trump's successful presidential campaign in 2016.

After months of refusing to assist Mueller's probe, Manafort finally took a plea deal in September and agreed to co-operate in return for reduced charges.

Manafort appeared in court in green prison uniform that said "Alexandria inmate." He was in a wheelchair and had a bandage on his right foot. A source familiar with his health said he had a "serious medical condition related to his diet."

Manafort had asked permission to wear a suit but Ellis rejected the request, saying he should be treated no differently from other defendants in custody after conviction.