Rosenstein, in a speech before the Greater Baltimore Committee's (GBC) annual meeting, described the firing as a difficult judgment call that was made after Comey strayed from the long-standing practices the FBI and the Department of Justice (DOJ) adhere to when dealing with open investigations.

The recently retired DOJ official also defended his oversight of the counterintelligence investigation into whether members of the Trump campaign conspired with Russia to win the 2016 election amid criticism that Comey’s firing was an attempt to obstruct the probe, which was ultimately completed by special counsel Robert Mueller.

"I would never have allowed anyone to interfere with the investigation," Rosenstein told the GBC, according to prepared remarks.

The White House initially pinned the decision to fire Comey on Rosenstein’s May 9, 2017, memo, a three-page document that transformed the former deputy attorney general from a little-known Justice Department official to one of the most scrutinized officials in the Russia probe. Trump later told NBC News’s Lester Holt that the Russia investigation factored into his thinking and that he would have fired Comey "regardless of recommendation."

Mueller investigated Comey’s firing among roughly a dozen episodes of possible obstruction of justice by Trump. The special counsel ultimately did not reach a conclusion on whether Trump obstructed the probe, writing in his report that his investigators could not "conclusively" determine Trump did not commit a crime.

Rosenstein said Monday that no one told him that Comey’s ouster "was intended to influence the course" of the Justice Department’s investigation into Russia's interference.

"The special counsel’s report states that the president’s counsel advised me on a Monday afternoon that the president had decided to remove the director," Rosenstein said. "It was news to me. Nobody said that the removal was intended to influence the course of my Russia investigation."

Rosenstein pointed to Comey’s unprecedented decisions surrounding the FBI’s investigation into Hillary Clinton’s handling of classified materials while secretary of State as the basis for his firing, stating that his actions "were not within the range of reasonable decisions."

Those actions include his decision to announce in July 2016 — without the consent of DOJ prosecutors or former Attorney General Loretta Lynch — that the FBI investigation had closed the Clinton email probe and that the bureau was not recommending criminal charges against Clinton as well as his subsequent decision to announce just days before the polls opened in 2016 that the bureau was reopening its investigation into Clinton's emails after additional records had been recovered.

"They were inconsistent with our goal of communicating to all FBI employees that they should respect the Attorney General’s role, refrain from disclosing information about criminal investigations, avoid disparaging uncharged persons, and above all, not take unnecessary steps that could influence an election," Rosenstein said.

According to Rosenstein’s account, the president shared a letter laying out his reasons for firing Comey before asking the No. 2 DOJ official to give then-Attorney General Jeff Sessions a memo outlining his concerns about Comey’s conduct the following morning.

Rosenstein, who left the Justice Department last week, noted that those who serve as the head of the FBI are often required to make tough choices. But he added that Comey, rather than reflecting on his mistakes, made it clear he stood by his decisions while testifying before Congress.

"In essence, he said that he would do it again if he had the chance," Rosenstein said.

Rosenstein said he would’ve handled the firing differently, but he defended the reasons he laid out in his memo.

"If I had been asked to make a recommendation before the removal decision was made, I would have included a more balanced analysis of the pros and cons. But my brief memo to the Attorney General is correct, and it was reasonable under the circumstances," Rosenstein said.

"If I had been the decision-maker, the removal would have been handled very differently, with far more respect and far less drama," he continued.

Rosenstein said he personally "admired" Comey for his leadership of the FBI and he did not "blame" him for being angry over his termination, but he also blasted the former director for since becoming "a partisan pundit" who has repeatedly attacked his character.

"Now the former Director is a partisan pundit, selling books and earning speaking fees while speculating about the strength of my character and the fate of my immortal soul," Rosenstein said. "That is disappointing. Speculating about souls is not a job for police and prosecutors. Generally we base our opinions on eyewitness testimony."