Testifying at a Senate hearing, Sessions, who was a close Trump adviser during the battle for the presidency, said it was a "detestable and appalling lie" to suggest that he participated in or was aware of any collusion between Russia and the Trump campaign.
In his dramatic appearance before former colleagues, Sessions also contradicted a contention made by former FBI Director James Comey at a hearing before the same panel last week. Comey told the intelligence committee that, after an encounter with President Trump in which he said Trump pressured him to back off an investigation into the former national security adviser, Comey "implored" Sessions to make sure he was never left alone with the president again - but that Sessions didn't respond.
"He didn't recall this, but I responded to his comment by agreeing that the FBI and Department of Justice needed to be careful to follow department policy regarding appropriate contacts with the White House," Sessions said.
The former Alabama senator defended himself against accusations that he misrepresented himself during his confirmation hearing by saying he hadn't met with Russian officials during the campaign. Sessions argued that in the context of that hearing, "my answer was a fair and correct response to the charge as I understood it."
Sessions said he recused himself from the Justice Department's current Russia investigation only because of a regulation that required it because of his involvement in the Trump campaign. He never, he insisted, knew anything about the Russia probe or had any role in it.
"Many have suggested that my recusal is because I felt I was a subject of the investigation myself, that I may have done something wrong," Sessions added. "But this is the reason I recused myself. I felt I was required to under the rules of the Department of Justice."
And while he had recused himself from the Russia probe, Sessions insisted, "I did not recuse myself from defending my honor against scurrilous and false allegations."
Despite Sessions' statement about the reasons for his recusal, the attorney general did not actually step aside from the Russia probe until March 2, the day after The Washington Post reported on his two previously undisclosed meetings with Russian Ambassador Sergey Kislyak. Days after that, Sessions also corrected his confirmation hearing testimony to inform the committee about the two meetings with Kislyak.
Democratic Sen. Ron Wyden of Oregon asked Sessions about suggestions arising from Comey's testimony last week that there was something "problematic" about his recusal.
Wyden asked Sessions what problematic issues existed.
"Why don't you tell me? There are none, Sen. Wyden, there are none," Sessions insisted, his voice rising. "This is a secret innuendo being leaked out there about me, and I don't appreciate it."
Sessions lent his support to the special counsel, Robert Mueller, who is now in charge of the Justice Department's Russia investigation. "I have confidence in Mr. Mueller," he said.
At a separate hearing Tuesday, Deputy Attorney General Rod Rosenstein, overseeing that effort since Sessions stepped aside, said he's seen no basis for firing Mueller, the former FBI director he appointed as special counsel.
He said he would agree to dismiss Mueller only if there were a legitimate basis to do so, and an order from the president would not necessarily qualify. Mueller also won votes of support Tuesday from the top two Republicans in Congress, House Speaker Paul Ryan of Wisconsin and Senate Majority Leader Mitch McConnell of Kentucky, both of whom said they have confidence in him.
As for his role in Comey's firing, Sessions told senators that he and his second-in-command, Rosenstein, had a "clear view ... that we had problems there, and it was my best judgment that a fresh start at the FBI was the appropriate thing to do. And when asked I said that to the president."
Asked about Trump's own contention that the president fired Comey with the Russia probe in mind, and regardless of any recommendation from anyone else, Sessions said: "I guess I'll just have to let his words speak for themselves. I'm not sure what was in his mind specifically."
Sessions refused to say whether he had ever discussed the Russia investigation with Trump, arguing that he could not disclose private communications with the president.
Democratic senators pressed Sessions on the legal rationale for his refusal to discuss those private conversations, as Sessions acknowledged that Trump had not asserted executive privilege around the hearing. He asserted that "I am protecting the right of the president to assert if it he chooses and there may be other privileges that may apply."
Ahead of the hearing there had been suggestions that Sessions might have had a third, unreported, encounter with Kislyak, at the Mayflower Hotel in April 2016, where candidate Trump was giving his first major foreign policy speech.
Sessions was adamant that he did not have a private meeting with Kislyak at that event. But he did allow for the possibility that he encountered him in a reception that he says was attended by a couple dozen people, though he said he had no specific recollection of that.
Democratic senators have seized on the possibility of a third meeting at that event to suggest that Sessions has not been forthcoming about the extent of his communications with the ambassador. Sens. Al Franken of Minnesota and Patrick Leahy of Vermont have sought an FBI investigation and have requested to be briefed on what the bureau knows about any such encounter.
On another hot-button issue, Sen. Marco Rubio, R-Fla., asked Sessions whether Trump records his conversations in the White House. Trump has suggested there might be tapes of his encounters with Comey; Comey said last week that "lordy" he hopes there are.
"I do not" Sessions said when asked whether he knows whether the president records his conversations.
"I don't know Sen. Rubio, probably so," Sessions added, when Rubio asked whether any such tapes would have to be preserved.
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