WASHINGTON – President Donald Trump sent a supportive message Tuesday to former national security adviser Michael Flynn, hours before Flynn's sentencing for lying to the FBI in the Russia investigation.

"Good luck today in court to General Michael Flynn," Trump tweeted as he again protested the investigation that has ensnared several members of his 2016 campaign and administration, including ex-campaign chairman Paul Manafort.

"Will be interesting to see what he has to say, despite tremendous pressure being put on him, about Russian Collusion in our great and, obviously, highly successful political campaign," Trump added. "There was no Collusion!"

Flynn is scheduled to be sentenced Tuesday morning, more than a year after he pleaded guilty to lying to FBI agents about his communications with Russian ambassador Sergey Kislyak after the 2016 election.

Special counsel Robert Mueller's team has recommended that Flynn receive no prison time following "substantial" cooperation with prosecutors in the ongoing investigation into Russian efforts to influence the election in Trump's favor.

Trump's salute to Flynn is in contrast to another witness in various investigations into his campaign: former personal attorney Michael Cohen, who was sentenced last week to three years in prison after pleading guilty to crimes that included campaign finance violations and tax evasion.

After his sentencing, Cohen said Trump directed him to make payments to women who claimed affairs with Trump because he worried about his chances in the 2016 election.

Trump described Cohen as a "rat" during a tweet storm on Sunday.

Flynn's sentencing comes a day after Flynn's onetime business partner and another associate were charged in an illegal lobbying effort on behalf of Turkey.

In February 2017, less than a month after they took office, Trump fired Flynn as national security adviser for lying about his discussions with Russian officials about sanctions leveled by the outgoing administration of President Barack Obama.

Flynn's problems played a key role in another aspect of the Russia investigation: the 2017 firing of FBI Director James Comey. Comey has said Trump had asked him to go easy on Flynn.

Mueller is investigating whether Comey's dismissal was part on an effort by Trump to obstruct justice in the Russia investigation.

Trump, who has denied obstruction as well as collusion, has said he fired Comey over performance issues.

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