A US Senate committee has said there is consensus that Russian Federation interfered in the 2016 presidential election, but the issue of collusion between Donald Trump's campaign team and Moscow is "still open".
The committee had spent many hours reviewing the assessment by the CIA and other intelligence agencies that Russian Federation interfered in the US election, Burr said, interviewing every person who helped craft it and examining intelligence from "the cutting room floor" not referenced in the assessment.
The House Intelligence Committee is conducting its own investigation of Russian election interference, as is Special Counsel Robert Mueller, who is also investigating whether the president sought to obstruct justice.
The white house is reiterating there was no collusion with Russian Federation.
Facebook shared the 3,000 ads with the House and Senate intelligence committees and the Senate judiciary committee.
Burr and the committee's vice chairman, Sen.
"Future witnesses that we might ask to come in the future, I strongly suggest you come in and speak with us", Burr said.
The news conference Burr and Warner held to provide a progress report on their monthslong probe underscored their investigation is growing in scope and is not shying away from the question of collusion - which Trump has repeatedly dismissed as a "hoax". "[It's] not a practice that we're going to get into".More news: Plane forced to land in Newfoundland after engine blowout
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The committee generally endorses the intelligence community's conclusions, he said. Burr said the panel and its staff have reached a "general consensus" that they trust the intelligence community's assessment that Moscow directed an influence campaign in the USA election.
"On the issue of collusion, the work of our committee. continues", he said.
In a report published in January four USA intelligence agencies said they took the dossier's allegations seriously. But he added that the 2016 election demonstrated "the Russian intelligence service is determined, clever and I recommend every campaign and every elected official take this seriously".
Burr said that both he and Warner made personal efforts to reach Steele, but he had not accepted their invitations.
Burr said Monday that he was opposed to releasing the advertisements publicly because he believes "no investigative body should be the source of sensitive documents, and I consider any document for this investigation sensitive".
Twitter will also appear in front of the committees on Thursday.
There has been some speculation that there is pressure on Burr to conclude the investigation, particularly from Trump circles, but he said that "the issue of collusion is still open".
"I also strongly believe that the RT ads on Twitter should be made public; a review of a representative sample reveals that they are nearly entirely created to push Russian news coverage adverse to Secretary Clinton's campaign", said Schiff in a statement.