Former FBI acting Director Andrew McCabe said he has no idea what President Donald Trump was talking about when the president slammed his as a 'poor man's J. Edgar Hoover.'

'I don't even know what that means,' he said Sunday on ABC's 'This Week.'

'You know, it's not the first time that I've had to listen to the president say bizarre and untrue things about me, so it's unfortunate this is getting a little bit routine,' he added.

Former FBI acting Director Andrew McCabe said he has no idea what President Trump was talking about when he called him a 'poor man's J. Edgar Hoover'

Donald Trump used his bully pulpit on Wednesday to marginalize former FBI deputy director Andrew McCabe and called him a 'poor man's J. Edgar Hoover'

Trump told reporters on Wednesday that McCabe is more perp than cop.

'I think Andrew McCabe has made a fool out of himself over the last couple of days, and he really looks to me like sort of a poor man's J. Edgar Hoover,' Trump said in the Oval Office.

'I think he's a disaster,' the president said. 'And what he was trying to do was terrible, and he was caught. I'm very proud to say we caught him.'

Then-Attorney General Jeff Sessions fired McCabe in 2018 less than two days before he was due to retire with a full government pension. He cited McCabe's 'lack of candor' to investigators probing press leaks about the FBI's investigation surrounding Democratic presidential candidate Hillary Clinton's classified email scandal.

'He is a disgraced man,' Trump said last week, citing the inspector general report that resulted.

McCabe is suing the Justice Department and the administration over his dismissal.

'It will be an action against the Department of Justice primarily in challenging the circumstances of my firing,' he told ABC.

'It, of course, derives from the inspector-general report, a report that I deeply disagree with, a report that was the result of a process that I don't think anyone has ever seen before. I certainly hadn't,' he said.

'There is no doubt in my mind that the president's clear desire impacted that process. The president was talking about removing me for months before I ever interacted with the inspector general. He made his desires perfectly clear on his own Twitter feed. The inspector general delivered that result,' McCabe said.

Trump has railed against McCabe, who became acting director of the FBI when James Comey was fired, as McCabe promotes his new book, 'The Threat: How the FBI Protects America in the Age of Terror and Trump.'

McCabe has conducted several interviews as part of his press tour for his book and he's held nothing back.

McCabe told '60 Minutes' how top Justice Department officials - in the wake of Trump's firing of FBI director James Comey - discussed convening the Cabinet to invoke the 25th amendment and remove Trump from office. He also confirmed Deputy Attorney Rod Rosenstein did offer to wear a wire during a White House meeting with Trump.

And he told NBC's 'Today Show' that he briefed the so-called 'Gang of Eight' on Capitol Hill, a group of the top congressional leaders from both parties, about the FBI's investigation into whether Trump was an agent for Russia and said neither Republicans nor Democrats raised any red flags at the time.

Despite Trump's nonstop complaints about McCabe, or perhaps because of them, McCabe's book 'The Threat' became an instant bestseller this week – outperforming every other book in Amazon.com's massive inventory

McCabe personally authorized two federal investigations into President Trump - one into Russia's role in the 2016 election and the other a counter intelligence investigation into whether Trump was an agent for Russia.

He said it was his decision to investigate Trump in regards to his relationship with Russia.

'I can tell you that the information that was in our hands at the time, much of which is publicly known, caused us great concern,' McCabe told 'This Week' on Sunday.

'This was the recommendation from the investigative team, and it was ultimately my decision to authorize the opening of the case. And I did that because at the time, the facts clearly indicated that we had an articulable basis to believe that a crime may have been committed and that a threat to national security might exist,' he added.

McCabe also urged the hiring of a special prosector after Trump fired Comey.

He was asked his assessment of special counsel Robert Mueller.

'I think first and foremost what you can expect from Robert Mueller is an honest, independent assessment of the work that they've done. How much detail he chooses to go into to convey to the Department of Justice is a great question. I hope they lean on the detailed side. This is not a normal investigation by any evaluation. It's one that I think the department, Congress and the public have enormous interest in finding out just exactly what they learned,' he said.