Two U.S. officials with direct knowledge told NBC News on Tuesday that briefing materials prepared for President-elect Donald Trump included information that initially circulated among Trump opponents and was passed to U.S. intelligence agencies making damaging allegations about his dealings with Russians.
Neither of the officials said the FBI was actively investigating the information, which has not been verified by U.S. agencies.
The sources would not comment on the nature of the allegations. The Trump transition team did not immediately respond to a request for comment.
But Trump himself did tweet at 8:19 p.m. ET Tuesday, in all caps, "FAKE NEWS — A TOTAL POLITICAL WITCH HUNT!"
It wasn't completely clear exactly what he was referring to, but other news outlets had already reported on the briefing materials.
Appearing Tuesday evening on NBC's "Late Night with Seth Meyers," Trump adviser Kellyanne Conway dismissed the reports as having possibly originated with a Russian investigator or groups that wanted Hillary Clinton to win the election.
And in an interview with NBC News before his farewell address Tuesday night in Chicago, President Barack Obama said he had not seen the news accounts of Trump's Russian ties but noted that "as a matter of principle and national security, I don't comment on classified information."
Related: President Obama Urges Citizens to Fight the 'Challenges to Our Democracy' in Farewell Speech
A declassified version of the report, which was released last week, concluded that a Russian covert operation designed to undermine American democracy evolved into an attempt to help Trump win the election.
Obama said he ordered the intelligence report "to make sure that we're working effectively with our allies so that misinformation and cyber attacks don't end up undermining democratic structures around the world."
"My expectation and my hope is that this work will continue after I leave, that Congress, in possession of both the classified and unclassified reports, that the president-elect and his administration, in possession of both the classified and unclassified reports, will take it seriously and now get to work reinforcing those mechanisms that we can use to protect our democracy," the president said.
More of the interview will be the focus of a "Dateline NBC" special airing Friday at 10 p.m. ET.
