Trump pardons former NSA Michael Flynn

US President Donald Trump has signed an executive order granting pardon to his former national security advisor Michael Flynn, who had been charged with making false statements to the FBI over possible collusion between the Trump campaign and Russia during the 2016 presidential polls.

Trump signed the executive order on Wednesday.

"It is my Great Honor to announce that General Michael T Flynn has been granted a Full Pardon. Congratulations to Gen Flynn and his wonderful family, I know you will now have a truly fantastic Thanksgiving!" Trump said in a tweet.

White House Press Secretary Kayleigh McEnany said, "The President has pardoned General Flynn because he should never have been prosecuted. An independent review of General Flynn's case by the Department of Justice — conducted by respected career professionals — supports this conclusion."

In fact, the Department of Justice has firmly concluded that the charges against Flynn should be dropped, she said.

"This Full Pardon achieves that objective, finally bringing to an end the relentless, partisan pursuit of an innocent man," she said.

"General Flynn should not require a pardon. He is an innocent man. Even the FBI agents who interviewed General Flynn did not think he was lying.

"Multiple investigations have produced evidence establishing that General Flynn was the victim of partisan government officials engaged in a coordinated attempt to subvert the election of 2016," McEnany said.

These individuals sought to prevent Donald Trump from being elected to the Presidency, to block him from assuming that office upon his election, to remove him from office after his inauguration, and to undermine his administration at every turn, she said.

House Speaker Nancy Pelosi in a statement said Trump's pardoning of Michael Flynn, who twice pleaded guilty to lying to the FBI about his dealings with a foreign adversary, is an act of grave corruption and brazen abuse of power.

"Trump is again using the pardon power to protect those who lie to cover up his wrongdoing, just as he did when he commuted the sentence of campaign advisor Roger Stone, who was convicted on seven felony counts," she said.

"Flynn's actions constituted a serious and dangerous breach of our national security. He must be held accountable. Yet Trump and his team continue to put the president over the country, as they politicise justice to shield Flynn and Trump from the law," Pelosi said.

"Sadly, this pardon is further proof that Trump plans to use his final days in office to undermine the rule of law in the wake of his failed presidency. In the new Congress, it is imperative that we pass House and Senate Democrats' Protecting Our Democracy Act, which prevents any president from abusing the pardon power," she said.

House Judiciary Committee Chairman Jerrold Nadler said the pardon is undeserved, unprincipled, and one more stain on President Trump's rapidly diminishing legacy.

"Michael Flynn was fired from the White House for lying to senior officials. He pleaded guilty twice to lying to federal investigators about his communications with a foreign adversary," he said.

"Flynn's agreement to cooperate with the government in exchange for those guilty pleas seemed light to some, given reports that Flynn and his son had engaged in far more disturbing criminal activity," he said.