Former acting FBI director Andrew McCabe said in an interview that aired Thursday that he authorized an investigation into President Trump’s ties to Russia a day after meeting with him in May 2017 out of fear that he could soon be fired.

“I was very concerned that I was able to put the Russia case on absolutely solid ground in an indelible fashion that, were I removed quickly or reassigned or fired, that the case could not be closed or vanish in the night without a trace,” McCabe told CBS.

The comments marked the first time that McCabe has publicly addressed why he opened an investigation into Trump following the firing of FBI Director James B. Comey, whose post McCabe took over. They came as CBS broadcast a portion of an interview scheduled to air in full Sunday on “60 Minutes.”

The clip — and journalist Scott Pelley’s description of what else he and McCabe talked about — suggests the onetime top official plans to pull back the curtain on law enforcement’s response to the new president as he promotes his book — “The Threat” — that is set to released next week. Pelley said that McCabe, in addition to talking about his interactions with Trump, described conversations officials had about using the 25th Amendment to oust the president.

The Washington Post and others have previously reported that McCabe alleges those conversations involved Deputy Attorney General Rod J. Rosenstein — though Rosenstein vaguely disputes that. McCabe’s mentioning the discussions on “60 Minutes” dredged up old tensions between the two men, in addition to provoking a sharp response from Trump.

About two hours after the clip aired, Trump blasted McCabe on Twitter, calling him “a disgrace to the FBI and a disgrace to our Country.” The Justice Department also disputed some of what McCabe contended.

“Disgraced FBI Acting Director Andrew McCabe pretends to be a ‘poor little Angel’ when in fact he was a big part of the Crooked Hillary Scandal & the Russia Hoax — a puppet for Leakin’ James Comey,” the president wrote, referring to an FBI investigation into Democrat Hillary Clinton’s use of a personal email server while secretary of state, in addition to its probe of possible coordination between the Trump campaign and Russia.

Senate Judiciary Chairman Lindsey O. Graham (R-S.C.) said in a statement that the CBS interview made it “imperative” that McCabe appear before his committee to answer for “what appears to be, now more than ever, bias against President Trump.”

It already had been reported that, in the wake of Comey’s firing, the FBI began to explore at that point whether Trump was trying to obstruct justice, and whether the president personally was of concern from a counterintelligence perspective. In the clip that aired on CBS, McCabe did not address specific evidence that led him to believe Trump should be investigated personally.

But McCabe’s talking about his mind-set during that time period was revelatory. Some at the Justice Department had been concerned McCabe might have acted too hastily to open a case because of Comey’s removal, people familiar with the matter have said.

McCabe also apparently addressed in the interview explosive allegations he made in memos documenting discussions with Rosenstein — although those clips have yet to air. It has been reported previously that McCabe alleged in the memos that Rosenstein suggested wearing a wire to surreptitiously record the president and/or invoking the 25th Amendment to remove Trump from office.

During an appearance on “CBS This Morning,” Pelley, the correspondent who interviewed McCabe, described the discussions of the 25th Amendment as “counting noses” — or speculating on where various Cabinet members might stand on the question.

Pelley said McCabe disputes the assertion, advanced by defenders of Rosenstein, that the deputy attorney general was not serious about wearing a wire. Pelley said McCabe took the idea to FBI lawyers for a discussion afterward.

That, too, has been previously reported, though McCabe has never before publicly described his allegations.

In a statement, a Justice Department spokesman said McCabe’s recitation of events — at least according to a transcript reviewed by officials — was “inaccurate and factually incorrect.”

The spokesman repeated Rosenstein’s previous response to McCabe’s version of his comments on wearing a wire and invoking the 25th Amendment, saying: “The Deputy Attorney General never authorized any recording that Mr. McCabe references. As the Deputy Attorney General previously has stated, based on his personal dealings with the President, there is no basis to invoke the 25th Amendment, nor was the DAG in a position to consider invoking the 25th Amendment.”

The spokesman also claimed, for the first time, that after Robert S. Mueller III was installed as special counsel, Rosenstein “directed that Mr. McCabe be removed from any participation in that investigation.”

The meaning of that was not immediately clear. At a Senate Intelligence Committee hearing in June 2017, the month after Mueller was appointed, McCabe, appearing with Rosenstein, talked of the FBI’s providing resources to the special counsel — implying he was still involved, at least in that respect.

“We have a robust relationship with the special counsel’s office, and we are supporting them with personnel and resources in any way they request,” he said.

At the same hearing, McCabe confirmed he was fully familiar with the scope of Mueller’s investigation, though he noted that Mueller was still sorting out some details of it. And that same month, he signed a Foreign Intelligence Surveillance Act warrant that would allow the FBI to continue surreptitiously monitoring former Trump campaign adviser Carter Page, one of the early subjects of the Russia probe.

As the clip of McCabe’s interview aired on CBS, the Atlantic published an excerpt of McCabe’s book, in which he describes his interactions with the president after Comey’s firing.

In one encounter that he seems to view as particularly troubling, McCabe wrote that Trump pressed in an Oval Office meeting to visit the FBI, even though he had just fired its well-liked leader. In McCabe’s view, Trump was trying to enlist McCabe in a plan to send a sinister message to employees that he had McCabe’s protection.

A frequent punching bag for Trump, McCabe was fired from the bureau in March just 26 hours before he could retire, after the inspector general presented Justice Department leadership with allegations that McCabe had authorized a disclosure to the media and then lied repeatedly to investigators about it. The timing of the firing cost McCabe a significant portion of his retirement benefits.

McCabe has said that his termination was politically motivated and meant to discredit the bureau and the ongoing Russia probe.