US President Donald Trump’s former campaign chairman Paul Manafort has been charged with residential mortgage fraud and other felonies, less than an hour after the 69-year-old was given his second federal prison sentence this month.

The 16-count indictment was announced by Manhattan District Attorney Cyrus Vance on Wednesday (New York time) as state politicians move to ensure that Mr Trump’s former adviser can be prosecuted, even if he receives a presidential pardon.

“No one is beyond the law in New York”, and the state probe “yielded serious criminal charges for which the defendant has not been held accountable”, Mr Vance said.

In Washington on Wednesday, US District Judge Amy Berman Jackson sentenced Manafort to about 3-1/2 additional years in prison on conspiracy charges from Special Counsel Robert Mueller’s probe into Russia’s role in the 2016 US presidential election.

Manafort had already been sentenced by a judge in Virginia to nearly four years’ jail, following his conviction last August on tax evasion and bank fraud charges related to the Mueller probe.

His total sentence was discounted by nine months for time already served while the cases unfolded.

Judge Jackson sentenced Manafort to six years and one month for two conspiracy counts to which he pleaded guilty in September 2018, related to money laundering, unregistered lobbying and attempted witness tampering.

She said two and a half years of the sentence would run at the same time as the sentence in Virginia.

Unlike at his sentencing hearing last week, Manafort said he was sorry for his actions, but Judge Jackson then told him his expression of remorse rang hollow.

She told Manafort that he had lied repeatedly and committed fraud repeatedly, and there was no good explanation for the leniency he sought.

“Saying ‘I’m sorry I got caught’ is not an inspiring plea for leniency,” Judge Jackson told Manafort, who was brought into the courtroom in a wheelchair because of gout.

Manafort, a veteran Republican political operative who earned millions of dollars working for pro-Russia politicians in Ukraine, had not showed any remorse at his sentencing in his other case last Thursday.

“I am sorry for what I have done and for all the activities that have gotten us here today,” he told the court on Thursday.

“This case has taken everything from me already – my properties, my cash, my life insurance, trust accounts for my children and grandchildren, and even more.” 

Mr Trump has denied colluding with Moscow and the Kremlin has denied election interference.

Mr Trump, who in November said he had not ruled out giving Manafort a pardon, said on Wednesday that “I have not even given it a thought”.

“It’s not something that’s right now in my mind. I do feel badly for Paul Manafort – that I can tell you,” the Republican president said.

Kevin Downing, a lawyer for Manafort, had no comment on the New York case following his client’s sentencing by Judge Jackson.

In a text message, Rudolph Giuliani, a lawyer for the Republican president and New York City’s former mayor, called the indictment an “irrational attempt” by Democrats to advance their political agenda.

Mr Vance said the charges in the March 7 indictment related to a year-long scheme in which Manafort and others falsified records to obtain millions of dollars related to property loans.

Manafort faces up to 25 years in prison on the three most serious charges in the latest indictment, residential mortgage fraud in the first degree.

Some charges appeared to relate to testimony in Manafort’s Virginia trial, including his alleged effort to disclaim a big American Express bill for season tickets to New York Yankees baseball games to help him qualify for loans.

-with AAP