Former FBI Director James Comey. AP Photo/Alex Brandon

The Senate Intelligence Committee sent two letters on Wednesday to former FBI Director James Comey and Acting FBI Director Andrew McCabe requesting their cooperation in the committee's ongoing investigation into Russia's election interference, and whether President Donald Trump's campaign was involved.

The senators have requested that Comey —who was fired by Trump last week — appear before the committee "in both open and closed sessions," according to a statement.

Comey had previously declined an invitation to speak before the committee in a closed session, senators said last week. A close Comey associate told The New York Times last week that he "is willing to testify, but wants it to be in public."

The Times reported Tuesday evening that Trump asked Comey to end the bureau's investigation into former National Security Adviser Michael Flynn, leaving lawmakers on both sides of the aisle shell-shocked — and openly discussing the possibility of impeachment proceedings.

Comey reportedly kept detailed memos relating to what he felt were "improper efforts" by Trump "to influence" the FBI's ongoing investigation, according to the Times. One of those memos detailed the February 14 meeting in which Trump asked if the director whether he could see a "way clear to letting this go, to letting Flynn go," noting that he's a "good guy."

The intelligence committee is now hoping that McCabe, the acting FBI Director, will hand over the memos Comey wrote "regarding any communications he may have had with senior White House and Department of Justice officials" related to the Russia probe.

Acting FBI Director Andrew McCabe listens on Capitol Hill in Washington, Thursday, May 11, 2017, while testifying before the Senate Intelligence Committee hearing on worldwide threats. Jacquelyn Martin/AP

The Senate Judiciary Committee also sent a letter to McCabe on Wednesday requesting "all such memos, if they exist, that Mr. Comey created memorializing interactions he had with Presidents Trump and Obama, Attorneys General Sessions and Lynch, and Deputy Attorneys General Rosenstein, Boente, and Yates regarding the investigations of Trump associates' alleged connections with Russia or the Clinton email investigation."

The Judiciary Committee also requested any "recordings, transcripts, notes, summaries, and memoranda" relating to the FBI's Trump-Russia probe from White House counsel Don McGahn. Trump tweeted on Friday that Comey had "better hope there aren't any 'tapes'" of the conversations they had while he was FBI Director, fueling calls from lawmakers for the White House to release any such recordings if they exist.

The Judiciary Committee wants all documents by May 24.

McCabe told the Senate Judiciary Committee last week that the FBI investigation into Russian interference in the US election was "highly significant," contradicting the White House's assertion that it was a low priority for the bureau.

He also said "there has been no effort [by the White House] to impede our investigation to date." It is unclear whether he knew about Comey's memo, but The Times said it was shared with senior FBI officials. McCabe was deputy director at the time.

A White House official said in a statement on Tuesday that Trump "has repeatedly expressed his view that General Flynn is a decent man who served and protected our country," but that he "has never asked Mr. Comey or anyone else to end any investigation, including any investigation involving General Flynn."

"The President has the utmost respect for our law enforcement agencies, and all investigations," the statement continued. "This is not a truthful or accurate portrayal of the conversation between the President and Mr. Comey."