Donald Trump remained mostly silent after his former personal fixer and lawyer Michael Cohen was handed a three year jail-term.

Cohen was sentenced for making illegal pay-offs during the 2016 campaign to keep a porn star and a Playboy model silent about their alleged affairs with US President Donald Trump.

The sentence imposed by Manhattan federal Judge William Pauley III was well below the maximum five-plus years Cohen had faced under non-binding guidelines, but more than the no-jail sentence sought by his lawyer for his co-operation with Special Counsel Robert Mueller’s Russia probe.

Cohen’s lawyer, Guy Petrillo, said his client was a brave witness who came forward with evidence “against the most powerful person in our country”.

But Mr Trump said back, reportedly telling associates “he’s a liar” after Cohen was sentenced - according to CNN.

The president has kept hush today as reporters pressed for a reaction to Cohen’s allegations which implicate Trump in federal crimes if true.

The White House has not officially commented on Cohen today.

The president tweeted about Cohen last week: “He lied for this outcome and should, in my opinion, serve a full and complete sentence.”

Mr Trump has denied any wrong doing.

Cohen will also have to pay $US2 million ($2.7 million) in combined restitution and fines.

He must report to the federal prison in Otisville, New York, an upstate minimum security prison.

Before learning his fate, Mr Trump’s former personal lawyer and longtime “fixer” — who once vowed that he’d “take a bullet for the president” — told the judge that Mr Trump had led him “to choose a path of darkness over light.”

“Recently, the president tweeted a statement calling me weak, and he was correct — but for a much different reason,” Cohen said. “Time and again I felt it was my duty to cover up his dirty deeds rather than listen to my own voice.”

“Today is the day I am getting my freedom back,” added Cohen, who later broke down in tears.

“I have been living in a personal and mental incarceration ever since the day that I accepted the offer to work for a real estate mogul whose business acumen that I deeply admired.”

Among the charges against Cohen was making “hush money” payments to Stormy Daniels and Karen McDougal who had threatened to go public during the 2016 presidential election campaign with claims they had affairs with Mr Trump.

Mr Trump this week sought to minimise the importance of the payments saying they were a “simple private transaction” and that they were “wrongly” being called campaign contributions.

Judge William Pauley said Cohen “should have known better” as a lawyer and that his co-operation with the Russia probe “does not wipe the slate clean.”

TABLOID PUBLISHER AVOIDS CHARGES
Meanwhile the publisher of US tabloid the National Enquirer has reached a deal with prosecutors to avoid charges over its role in paying hush money.

Ms McDougal has said she sold the story of a months-long affair with Donald Trump for $US150,000 ($A207,698) to American Media Inc but it was never published.

The incident involved a practice known as “catch and kill”, designed to prevent a potentially damaging article from being published.

In a statement, the US Attorney’s Office for the Southern District said it agreed not to prosecute AMI after the company admitted it made the $US150,000 payment “in concert with a candidate’s presidential campaign, and in order to ensure that the woman did not publicise damaging allegations about the candidate before the 2016 presidential election”.

Prosecutors announced the agreement on the same day Cohen was sentenced.

AMI’s chief executive officer David Pecker, a longtime friend of Trump and Cohen, had met with prosecutors to describe their hush-money deals with Ms McDougal and Ms Daniels ahead of the 2016 US election, the Wall Street Journal reported in August.

Pecker and another AMI executive were granted immunity as part of prosecutors’ probe, Vanity Fair also reported.

Ms Daniels’ lawyer Michael Avenatti said Cohen deserved to go to prison.

“This nation owes a sense of gratitude to my client Stormy Daniels. We will not stop until the truth is known relating to the conduct of Donald Trump. Let me be clear, Michael Cohen is neither a hero nor a patriot. He lied for months on end about his criminal conduct and the role of the president of the United States. He lied in March, he lied in April, he lied in May, he lied in June, he lied in July, and only until his back was against the wall and he faced significant prison time did he decide to ‘come clean’,” he said.

“His choice time and time again was to degrade my client, seek to intimidate her, call her and me liars and seek to degrade the office of the presidency of the United States but seeking to buy effectively an election. This is an outrage. He deserves every day of the 36 month sentence that he will serve”.

“Michael Cohen was sentenced today, Donald Trump is next,” he said.