The Senate Select Committee on Intelligence said it will conduct a bipartisan inquiry into possible Russian intelligence agencies' involvement in the U.S. election, and the probe's scope includes interviewing officials in the Obama and Trump administrations.
"We believe that it is critical to have a full understanding of the scope of Russian intelligence activities impacting the United States," committee chairman Sen. Richard Burr and vice chairman Sen. Mark Warner said in a statement.
The inquiry will include "any intelligence regarding links between Russia and individuals associated with political campaigns," the committee said.
The Senate committee plans to "interview senior officials of both the outgoing and incoming administrations including the issuance of subpoenas if necessary to compel testimony."
The probe comes after U.S. intelligence agencies concluded that the Russian government was likely involved in a covert campaign to interfere in the U.S. election and carry out cyber-attacks on Democratic Party organizations.
The statement by Burr, a Republican, and Warner, a Democrat, said "the committee will follow the intelligence wherever it leads."
President-elect Donald Trump had cast doubt on U.S. intelligence assessments that Russia was involved, but on Wednesday he said at a press conference, "As far as hacking, I think it's Russia." Russia has denied any involvement.
The allegations of Russian attempts to interfere in the U.S. presidential election has caused some opponents to doubt the legitimacy of Trump's impending presidency, while Trump and other Republicans have repeated that any Russian campaign did not affect the outcome.
On Friday Democratic Rep. John Lewis, a civil rights leader, told NBC's "Meet the Press" that "I don't see this president-elect as a legitimate president," citing the alleged Russian campaign.