Sessions, who was confirmed as attorney general earlier this year, was first criticized for not disclosing during his Senate confirmation hearing that he had been in contact with the Russian ambassador to the United States.
New questions about Sessions were raised last week, after former FBI Director James Comey said that he and other leaders at the agency had expected Sessions to recuse himself weeks before he did - and that the reasons behind that thinking are classified.
Sessions may be under a further cloud after Comey suggested the attorney general may have failed to take appropriate steps to protect the Federal Bureau of Investigation chief.
Ruddy said in an interview Monday with Judy Woodruff of PBS, "I think he's weighing that option". Comey said that Trump pressured him to drop the FBI's investigation into former National Security Advisor Michael Flynn and demanded Comey's loyalty during the one-on-one meetings he had with president.
The Justice Department said Sessions requested that the hearing, which will begin at 2:30 p.m. (1830GMT), be public.
The Senate investigation is one of three Russian Federation inquiries, including one being headed by the FBI. "He says he was involved in the firing of Comey, and the President said Comey was sacked because of Russian Federation".
The attorney general may also face questions on this.
Deputy Attorney General Rod Rosenstein testifies on Capitol Hill in Washington, Tuesday, June 13, 2017, before a Senate Appropriations subcommittee hearing on the Justice Department's fiscal 2018 budget.
The White House has denied any collusion with Moscow.
Spicer, the spokesman, declined to say then that Sessions enjoyed Trump's confidence, though spokeswoman Sarah Huckabee Sanders said later in the week that the president had confidence "in all of his Cabinet". With Trump, you can never say never, but don't bet on it.
During his testimony last week, Comey said he had notes of meetings with Trump in which the president asked him for a pledge of personal loyalty and to drop the Russian Federation investigation as it pertained to former national security adviser Flynn.
In a letter to the committee, he agreed to answer questions about his contacts with the Russians as well as his take on if the president tried to end the Russia probe. "The Washington Post and USA Today report that Sessions' appearance is expected to be closed".
Democratic Senator Dianne Feinstein, a member of both the Senate intelligence and judiciary committees, has said Sessions should answer questions about his January testimony.