Given that as Federal Bureau of Investigation director Comey was overseeing the probe into Russian Federation and its possible collusion with the Trump team, the firing has led to questions about potential obstruction of justice.
The matter that Comey declined to disclose appears to refer to an ongoing inquiry over whether Sessions failed to disclose a third meeting with the Russian ambassador during a April 16 campaign event for then-presidential candidate Trump.
The Senate Intelligence Committee will get its chance Tuesday to hear from Attorney General Jeff Sessions under oath.
Trump told reporters Friday he'd have something to say about the tapes "soon", but White House officials haven't given a solid answer about whether they exist - though members of Congress have called for them as evidence if they do.
"We need to talk about the Russian Federation meetings, the meetings with the ambassadors", Rep. Adam Kinzinger told CNN's Kate Bolduan on "At This Hour".
During a White House meeting Monday, cabinet members including Sessions offered a chorus of flattery for the president despite the crises buffeting the administration.
Sessions, a former Republican senator from Alabama, will face tough questions from his former colleagues on a number of fronts that he has never had to publicly address in detail. Comey alleges that Trump then privately asked him to drop a probe into former national security adviser Michael Flynn's contacts with Russian Federation.
The announcement caps the drama that started over the weekend when Sessions canceled two appearances Tuesday, citing former Comey's blistering testimony last week.
SKorea leader proposes Asian nations co-host 2030 World Cup
If Chain win the bid for 2030 World Cup then they will be the most populated nation to host the FIFA World Cup. The Singaporean referee will be assisted by a fellow Singaporean and two officials from Malaysia.
She said Sessions should also testify before the Judiciary Committee, because it was better suited to explore legal questions of possible obstruction.
Comey also has said Sessions did not respond when he complained he did not "want to get time alone with the President again". But senators on the committee are expected to question Sessions about his meetings with Russians - a topic that has come under increased scrutiny amid investigations into Russia's interference in the USA election. On Saturday, he wrote the chairmen of both committees and said he was sending his deputy attorney general to testify in his place. It is not yet known whether the hearing will be public or closed.
"As NPR's Carrie Johnson recently reported on All Things Considered: "[Sources] are telling me Trump has been very angry with Jeff Sessions for recusing himself in the Russian Federation investigation to begin with, lots of profane conversations and yelling.
"I have a recollection of him just kind of looking at me", Comey testified.
What's more, Trump reportedly tasked Sessions with coming up with the case for firing Comey.
"I don't think we finish those whole conversations until we just know everything, so I just want more information about everything that can come out", the IL lawmaker said.