U.S. Attorney General Jeff Sessions, whose contacts with Russia's ambassador to the U.S. during the presidential campaign have sparked questions, has agreed to appear before the Senate intelligence committee on Tuesday as it investigates alleged Russian meddling in the election.

Sessions recused himself in March from a federal investigation into contacts between Russia and the presidential campaign of Donald Trump after acknowledging that he had met twice last year with the Russian ambassador to the U.S. He had told lawmakers at his January confirmation hearing that he had not met with Russians during the campaign.

Sessions has been dogged by questions about possible additional encounters with the ambassador, Sergey Kislyak. Senate Democrats have raised questions about whether the men met at an April 2016 foreign policy event at the Mayflower Hotel in Washington. The Justice Department has said that while Sessions was there, for a speech by Trump, there were no meetings or private encounters.

Former FBI Director James Comey raised additional questions at a hearing on Thursday, saying that the FBI expected Sessions to recuse himself weeks before he actually did. Comey declined to elaborate in an open setting.

Sessions, right, shakes hands with then-FBI Director James Comey in Washington on Feb. 9. In a letter Saturday, Sessions wrote that his decision to appear comes in light of last week's testimony by Comey. (Susan Walsh/Associated Press)

Sessions compelled by Comey's testimony

In a letter Saturday to Senator Richard Shelby, a Republican from Alabama, Sessions said that he had been scheduled to discuss the Justice Department budget before House and Senate appropriations subcommittees, but that it had become clear some members would focus their questions on the Russia investigation. Shelby chairs the Senate appropriations subcommittee.

Sessions said his decision to accept the intelligence committee's invitation to appear was due in part to Comey's testimony. He wrote that "it is important that I have an opportunity to address these matters in the appropriate forum." He said Deputy Attorney General Rod Rosenstein would appear before the subcommittees.

Briefing congressional appropriators on the Justice Department's budget is a critical part of the attorney general's job. The fact that Sessions would delegate that task to his deputy showed the Russia investigation was distracting him from his core duties.

Sessions did not say in the letter whether his appearance would be in public or behind closed doors. Comey testified in public and then met with the committee in a closed session to discuss matters touching on classified information.