President Donald Trump's former campaign chairman Paul Manafort was sentenced on Wednesday to three and a half more years in prison for charges arising from Special Counsel Robert Mueller's probe into Russia's role in the 2016 US election.

The sentence of 73 months in prison imposed by US District Judge Amy Berman Jackson in Washington came six days after a different judge gave Manafort a lenient term of 47 months - just under four years - in prison in a separate case in Virginia.

Jackson said 30 months of her sentence will run at the same time as the sentence in the Virginia case. That means the combined sentence will be 90 months - seven and a half years. With time already served Manafort will end his sentence in six years and nine months.

Manafort was later charged with further crimes in New York, including an alleged year-long residential mortgage fraud scheme that netted millions of dollars, prosecutors claimed..

If convicted the the state charges could carry a potential sentence of up to 25 years, and were seen as a strategy for preventing a potential presidential pardon.

Manhattan District Attorney Cyrus Vance unveiled a total of 16 state charges, which could not be pardoned by Mr Trump in the event of convictions because they are state-level.