The CNN anchor began by fact-checking Sean Spicer, the future White House press secretary, who, while opening Trump's first press conference in six months, suggested that both BuzzFeed and CNN had published the uncorroborated dossier.
"That's not true. That's false. CNN never did that," said Tapper, who reported the story
with Carl Bernstein, Jim Sciutto and Evan Perez.
CNN broke the story, but, unlike BuzzFeed, did not publish the 35-page dossier, Tapper pointed out.
Tapper also stood by CNN's reporting on the classified documents, which include allegations that Russian operatives claim to have compromising personal and financial information about Trump.
"No one has disputed that the two-page synopsis was in the presentation by the intelligence chiefs to President-elect Trump, to President Obama," he emphasized, adding that CNN gave Trump and his team ample chance to comment on the story before it aired and was published online.
As for Trump's refusal to give a question to CNN's Jim Acosta during the press conference, branding CNN as "fake news," Tapper had strong words, implying that CNN and BuzzFeed's individual reporting should not be conflated.
"What I suspect we are seeing here is an attempt to discredit legitimate, responsible attempts to report on this incoming administration (by conflating them) with irresponsible journalism that hurts us all, and the media going forward should keep that in mind," he said.
After co-anchor Wolf Blitzer asked if he was referring specifically to BuzzFeed's decision to publish the dossier in full, Tapper said yes.
"It's irresponsible to put uncorroborated information on the Internet," he said.
"That's why we did not publish it, and why we did not detail any specifics from it, because it was uncorroborated and that's not what we do," Tapper added. "We are in the business of sussing out what is true and what is false."
In an official statement released Wednesday
, CNN said, "We are fully confident in our reporting."