WASHINGTON (Reuters) - U.S. President Donald Trump described a demand by prosecutors on Monday for a federal judge to sentence his longtime adviser Roger Stone to 7-9 years in prison as “horrible and very unfair” and said such a “miscarriage of justice” should not be allowed.

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Stone is due to face sentencing by U.S. District Court Judge Amy Berman Jackson on Feb. 20, after a jury in November found the self-proclaimed “dirty trickster” guilty on seven counts of lying to Congress, obstruction and witness tampering.

The government said that under U.S. sentencing guidelines, he faces a range of seven years and three months to up to nine years, and told Jackson he “should be punished in accord” with those. Such a term would “accurately reflect the seriousness of his crimes and promote respect for the law”.

Stone is one of several people close to Trump who faced charges stemming from then-Special Counsel Robert Mueller’s investigation into Russian interference in the 2016 presidential election.

"This is a horrible and very unfair situation. The real crimes were on the other side, as nothing happens to them. Cannot allow this miscarriage of justice!" Trump said on Twitter here after midnight on Monday.

Trump has the power to pardon people for federal crimes, although he has yet to use it in the cases of other former aides convicted in the wake of the Mueller investigations.

During the trial, prosecutors pressed their case that Stone lied to lawmakers about his outreach to WikiLeaks - the website that disclosed many hacked Democratic emails ahead of the 2016 U.S. election that proved embarrassing to Trump’s Democratic opponent Hillary Clinton - to protect Trump from looking bad.

Stone, who has labeled himself an “agent provocateur” and has the face of former President Richard Nixon tattooed on his back, was charged with obstructing justice, witness tampering and lying to the U.S. House of Representatives’ Intelligence Committee during its investigation into Russian election interference.

Stone’s colorful trial featured references to the film “The Godfather Part II,” an impression of Senator Bernie Sanders by prosecution witness Randy Credico, and testimony by political heavyweights including former Trump campaign chief executive Steve Bannon and former Trump deputy campaign chairman Rick Gates.

Those witnesses said they believed Stone had inside information about when WikiLeaks might release more damaging emails about Clinton. In truth, he had no such information.

Stone was also accused of tampering with Credico’s testimony, when Credico was summoned to testify before Congress and speak with the FBI. In emails and texts, Stone told Credico among other things: “Prepare to die,” “You’re a rat. A stoolie,” and “Stonewall it.”