Donald Trump’s war with CNN came to a head on Wednesday morning during the president-elect’s first press conference.

After he spent a good portion of the event railing against CNN, along with BuzzFeed, for reporting on a document that alleges Russia has “compromising personal and financial information” about him, Trump refused to let CNN’s Jim Acosta ask a question, shouting him down by saying, “You are fake news!”

When the press conference came to an end after a little more than an hour, it was left to CNN’s Jake Tapper to defend his organization’s reporting. “There are two categories of news,” he said of the press conference. “Let me take on the first one that has to do with us, CNN.”

“At the beginning of the press conference, Sean Spicer, who is going to be the White House press secretary, suggested that both BuzzFeed and CNN published this dossier full of uncorroborated rumors,” Tapper continued, referring to Spicer’s aggressive statement that opened the event. “That's not true. That's false. CNN never did that. We never provided even one detail from that dossier except this morning when I said that there was reason to believe that one detail that had been out there because of BuzzFeed was false involving Trump's attorney Michael Cohen.”

While BuzzFeed posted the full 35-page document, reportedly compiled by a former British MI6 agent about Russia’s alleged attempts to blackmail Trump, CNN only reported on the existence of the document, not its contents. That report, which features four bylines, including Tapper’s, stated that intelligence officials made both Trump and President Obama aware of the document’s existence in a classified briefing last week.

“That conflation, whether it's because Sean Spicer misunderstood or some other reason, that's not true,” Tapper said of the efforts to lump CNN and BuzzFeed together. “CNN did not do that.”

“When Mr. Trump went after our own Jim Acosta saying he is ‘fake news’ and he isn't going to call on him, what I suspect we are seeing here is an attempt to discredit legitimate, responsible attempts to report on this incoming administration with irresponsible journalism that hurts us all and the media going forward should keep that in mind,” Tapper added, confirming that he did find BuzzFeed’s decision to put “uncorroborated” information on the internet “irresponsible.”

“I can understand why President-Elect Trump would be upset about it,” Tapper said of the BuzzFeed report. “That's why we did not detail any specifics from it because it was uncorroborated and that's not what we do. We are in the business of sussing out what is true and false.”

A statement from a CNN spokesperson following the press conference echoed these sentiments and sought to differentiate the network’s reporting from BuzzFeed.

“CNN’s decision to publish carefully sourced reporting about the operations of our government is vastly different than Buzzfeed’s decision to publish unsubstantiated memos. The Trump team knows this,” the statement reads.

“They are using BuzzFeed’s decision to deflect from CNN’s reporting, which has been matched by the other major news organizations. We are fully confident in our reporting. It represents the core of what the First Amendment protects, informing the people of the inner workings of their government; in this case, briefing materials prepared for President Obama and President-elect Trump last week. We made it clear that we were not publishing any of the details of the 35-page document because we have not corroborated the report’s allegations. Given that members of the Trump transition team have so vocally criticized our reporting, we encourage them to identify, specifically, what they believe to be inaccurate.”

BuzzFeed’s editor-in-chief Ben Smith similarly defended his site’s decision to publish the full document in a letter to staff on Tuesday night, admitting that it was not “simple call” and anticipating push back.

“Our presumption is to be transparent in our journalism and to share what we have with our readers. We have always erred on the side of publishing. In this case, the document was in wide circulation at the highest levels of American government and media,” Smith wrote.

“Publishing this document was not an easy or simple call, and people of good will may disagree with our choice. But publishing the dossier reflects how we see the job of reporters in 2017.”