WASHINGTON -- Former FBI Deputy Director Andrew McCabe says the Justice Department's decision to fire him just two days before his retirement is part of the Trump administration's "war on the FBI." McCabe, who briefly led the agency after Director James Comey was fired, said his dismissal by Attorney General Jeff Sessions on Friday night was the latest attack on his credibility.

He has claimed he's being singled out because of what he witnessed in the aftermath of Comey's ouster.

McCabe was fired a day after FBI ethics officials recommended his dismissal, reports CBS News justice correspondent Paula Reid, and just before the expected release of an Inspector General's report which is expected to show that he shared information with the media about the agency's investigation into the Clinton Foundation.

In a statement, Sessions said McCabe, "lacked candor -- including under oath -- on multiple occasions… all FBI employees know that lacking candor under oath results in dismissal."

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But McCabe pushed back hard, saying his firing is yet another attempt by the administration to undermine Special Counsel Robert Mueller's investigation into Russian meddling in the U.S. election process, and allegations that Mr. Trump's campaign colluded with those efforts.

In a statement, McCabe wrote that he was, "being singled out and treated this way because of the role I played, the actions I took and the events I witnessed in the aftermath of the firing of James Comey."

Part of Mueller's probe is looking into whether President Trump was trying to obstruct justice by firing Comey.

McCabe said in his statement that the inspector general's report was fast-tracked after he told the House Intelligence Committee he would corroborate Comey's accounts of conversations he had with the president. Comey has testified that Mr. Trump asked if he would end an investigation into former National Security Adviser Michael Flynn.

McCabe spoke directly about the ongoing Russia investigation in his statement.

"It is part of this administration's ongoing war on the FBI and the efforts of the special counsel investigation, which continue to this day," he said. "Their persistence in this campaign only highlights the importance of the special counsel's work."

President Trump tweeted shortly after midnight that it was a "great day" for the FBI and "Democracy," and he accused "sanctimonious" Comey of making McCabe, "seem like a choir boy."

Andrew McCabe FIRED, a great day for the hard working men and women of the FBI - A great day for Democracy. Sanctimonious James Comey was his boss and made McCabe look like a choirboy. He knew all about the lies and corruption going on at the highest levels of the FBI! — Donald J. Trump (@realDonaldTrump) March 17, 2018

In a phone interview with CBS News' senior investigator producer Pat Milton, McCabe said he rejected the findings in the (Inspector General's) report, calling it "misleading and unfair."

"I strongly believe this is the latest chapter in a yearlong attack on my credibility and service to the country," McCabe said.

In his statement, McCabe said "to have my career end in this way, and to be accused of lacking candor when at worst I was distracted in the midst of chaotic events, is incredibly disappointing and unfair. But it will not erase the important work I was privileged to be a part of, the results of which will in the end be revealed for the country to see."

McCabe said he was notified of his firing by a press release. The 49-year-old is likely to keep at least some of his pension.

Read McCabe's full statement or read the text below:

Before and after former FBI director James Comey met with President Trump in Feb. 2017, Comey and top FBI officials, including McCabe, were troubled by Mr. Trump's repeated attempts to meet alone with Comey, CBS News' justice and homeland security correspondent Jeff Pegues reports.

Most of the top FBI officials in on the discussions with Comey after his meetings with Mr. Trump have left the bureau in the past year, one way or another, Pegues reports. Comey and McCabe were fired.

The report by the Department of Justice Inspector General found evidence that McCabe had questionable contacts with a reporter and was not fully forthcoming when asked about it about an investigation concerning the Clinton Foundation. Those familiar with McCabe's side of the story say he was authorized to talk to reporters.

The decision came after Associate Deputy Attorney General Scott Schools met with McCabe Thursday, a part of an effort to shift the McCabe decision to "career officials" within the DOJ, according to a source familiar with the process. The optics, the source says, are not good for Attorney General Sessions to fire a career civil servant who is frequently criticized by the president. Schools is among the top career officials at the DOJ currently, and the department wanted to pin the outcome of the situation on long-established institutional norms, not politics.

President Trump has blasted McCabe in the past, particularly over his wife's acceptance of campaign cash from an ally of Hillary Clinton's, before McCabe began FBI's investigation of Clinton's email server. He also said McCabe was "racing the clock to retire with full benefits."