Michael Flynn, the former national security adviser. Mario Tama /Getty Images The ranking Democrat on the House Intelligence Committee said Friday that Michael Flynn's request for immunity from prosecution in exchange for his testimony was "a grave and momentous step" for the ousted national security adviser.

California Rep. Adam Schiff, whose committee is looking into President Donald Trump's campaign's potential ties to Russia, said it was far too early for any immunity requests to be considered.

"With respect to the offer by the attorney for Michael Flynn that he would be willing to testify before the House and Senate intelligence committees but only in exchange for immunity, we should first acknowledge what a grave a momentous step it is for a former national security adviser to the president of the United States to ask for immunity from prosecution," Schiff said in a statement. "We will be discussing the matter with our counterparts on the Senate Intelligence Committee and the Department of Justice."

Schiff added that while Flynn's testimony was "of great interest to our committee," the members were "deeply mindful" of the DOJ's interests in the case.

The FBI is also investigating potential collusion between the Trump campaign and Russian officials surrounding the election, Director James Comey said during a hearing before the committee last week.

"Additionally, as with any investigation — and particularly one that grows in severity and magnitude by the day — there is still much work and many more witnesses and documents to obtain before any immunity request from any witness can be considered," Schiff said.

As an example, Schiff said he was still waiting to receive documents on whether Flynn "properly reported any work he may have conducted on behalf of a foreign entity."

Rep. Adam Schiff, the ranking member of the House Intelligence Committee. Win McNamee/Getty Images

Late Thursday, The Wall Street Journal reported that Flynn offered to testify before both intelligence committees and the FBI in exchange for a guarantee he would not be subjected to "unfair prosecution," as outlined in a statement from his attorney. So far, none of the entities has accepted his offer.

Flynn's request has put him under intense scrutiny because of his comments last year about the partial immunity that aides to Democratic presidential nominee Hillary Clinton received in the FBI's investigation into her use of a private email server while she was secretary of state. Flynn told NBC's Chuck Todd in September that "when you are given immunity, that means you probably committed a crime."

Trump echoed that sentiment during a rally in Florida that month.

"If you're not guilty of a crime, what do you need immunity for, right?" Trump said.

In a statement on Thursday, Flynn's attorney, Robert Kelner, said Flynn "certainly has a story to tell, and he very much wants to tell it, should the circumstances permit."

"Notwithstanding his life of national service, the media are awash with unfounded allegations, outrageous claims of treason, and vicious innuendo directed against him," Kelner wrote. "He is now the target of unsubstantiated public demands by members of Congress and other political critics that he be criminally investigated.

"No reasonable person who has the benefit of advice from counsel would submit to questioning in such a highly politicized, witch hunt environment without assurances against unfair prosecution," he continued.

Trump said on Friday morning that Flynn was right to seek immunity.

"Mike Flynn should ask for immunity in that this is a witch hunt (excuse for big election loss), by media & Dems, of historic proportion!" Trump tweeted.

Flynn was ousted in February after he misled Vice President Mike Pence about the nature of his communications with the Russian ambassador, Sergey Kislyak, before Trump's inauguration.

Several other Trump associates and campaign officials, including Roger Stone, Paul Manafort, and Carter Page, have volunteered to be interviewed by Schiff's committee.