US Election 2016: Secret memo accuses FBI of abusing surveillance tools to probe Trump-Russia collusion

US President Donald Trump is set to approve the release of a controversial memo accusing the FBI of abusing its surveillance tools during its probe into alleged Russian collusion in the 2016 presidential election, setting up a clash with the intelligence agency.

The approval for the release of such a memo, which is being opposed by the FBI, could come as soon as tonight, US media reported.

A senior administration official, told reporters aboard Air Force One that the president is expected to tell Congress that he has no objections to the release of the memo written by House Intelligence Chairman Devin Nunes.

Requesting anonymity, the official said it is a Congressional process and that the decision was made after looking at the memo the last few days and making sure "it doesn't give away too much in terms of classification".

"The president is ok with it," the official said.

"I doubt there will be any redactions. It's in Congress' hands after that," the official said, and refused to answer any further questions.

Trump's reported decision comes a day after the FBI in an unusual move went public urging against release of the memo.

Some White House official fear that this might result in the resignation of FBI Director Christopher Wray.

Last year, Trump abruptly fired FBI chief James Comey for his handling of the Russia inquiry.

Trump publicly shamed Attorney General Jeff Sessions for his decision to recuse himself from the Russia case because of his prior contacts with Russia Ambassador Sergey Kislyak.

The potential release of the memo has set up a standoff with Trump against both the FBI and Department of Justice.

Although the President has signalled that he is inclined to release the memo, as part of an effort to undercut the special counsel Robert Mueller's investigation, senior officials inside the White House are trying to come up with a solution that satisfies both the President and law enforcement officials like Wray and Deputy Attorney General Rod Rosenstein, CNN said.

Intelligence officials warn the memo distorts facts and could jeopardise intelligence-gathering information.

Once Trump gives his approval, it would be up to the House intelligence committee to take a final call on the report's release.

Nunes is under pressure from the opposition Democrats and some of his own Republican lawmakers not to release the memo.

They side with officials of the FBI and many in the Department of Justice and feel the report is misleading and could expose sensitive and classified information.

On January 31, the FBI released a statement to express their "grave concerns about the material omissions of fact that fundamentally impact the memo's accuracy".

A top Democrat lawmaker, Adam Schiff, who is also a ranking member of the intelligence committee, has accused Nunes of altering the memo.

Democratic leader Nancy Pelosi issued a strong warning to the Republicans against issuing the memo.

"Speaker Paul Ryan, Chairman Nunes and House Republicans reckless decision to release a bogus, partisan memo, pushes the GOP's campaign to cover-up for President Trump to a new, completely unacceptable extreme," she alleged.

"It seems to reflect either a wilful disregard or ignorance of the importance of separation of three branches of government which seem to be eroding right now. So, that on its face is kind of disturbing," said James Clapper, the former Director of National Intelligence.

Meanwhile, House Judiciary Committee Ranking Member Jerrold Nadler sent a letter to Chairman Bob Goodlatte to request an emergency briefing with FBI Director Wray on his concerns regarding the memo.

The memo, Nadler alleged is "a set of misleading talking points drafted by the Republican staff of the House Permanent Select Committee on Intelligence.

"The White House plans to release it to the public in an attempt to discredit the FBI and undermine Special Counsel Robert Mueller s Russia investigation," Nadler said.

House Democratic Whip Steny H Hoyer said the report was intended "to undermine the Special Counsel's independent investigation into possible collusion between the Trump campaign and Russia".

In a separate statement, FBI Agents Association (FBIAA) president Thomas O'Connor opposed the release of the memo.

"The FBI Agents Association appreciates FBI Director Chris Wray standing shoulder to shoulder with the men and women of the FBI as we work together to protect our country from criminal and national security threats," said O'Connor.

He said the agency's special agents remain professional and focused on protecting the US from terrorists and criminals.

"Special agents take a solemn oath to our country and to the constitution, and the American public continues to be well-served by the world s preeminent law enforcement agency," he said.