The vice chairman of the Senate Intelligence Committee accused Russian President Vladimir Putin Thursday of ordering a "deliberate campaign carefully constructed to undermine" last year's presidential election.

Sen. Mark Warner, D-Va., made the charge as the Senate panel held a rare public hearing about Russia's meddling in the 2016 presidential campaign. In his opening statement, Committee Chairman Sen. Richard Burr, R-N.C., avoided any mention of last year's presidential campaign, but said efforts by Russia to "discredit the United States and weaken the West are not new."

Thursday's hearing focuses on how Russia has used its cyber capabilities to spread disinformation. Putin on Thursday again dismissed charges that he sought to disrupt the U.S. election as "endless and groundless."

At a news conference Wednesday, Burr and Warner pledged "to go wherever the intelligence leads us," in Burr's words, in their investigation. Their posture stands in stark contrast to the House Intelligence Committee probe, which has stalled after Committee Chairman Devin Nunes, R-Calif., reported he viewed intelligence documents on the White House grounds which he then briefed President Trump about, but refused to share with other committee members.

Democrats have called on Nunes, who also served on the Trump transition team, to recuse himself, but Nunes has said he sees no reason to do so.

The FBI is also conducting an investigation.

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