Veteran journalist Carl Bernstein issued a call to action for journalists ahead of President Trump's meeting with Russia President Vladimir Putin in Finland on Monday, saying "we've got a huge amount of reporting to do," and declared Trump's "witch hunt" grievance against the federal Russia investigation to be proven false.

During a CNN panel on Sunday, Bernstein explained how he was encouraged by Deputy Attorney General Rod Rosenstein announcing on Friday that special counsel Robert Mueller indicted 12 Russian officials on charges of hacking Democrats' computers during the 2016 campaign.

"We have to assume what we saw with Rod Rosenstein on Friday is very much part of the dynamic of Helsinki, and that indeed the president's object has been, throughout, to make this appear as a 'witch hunt,'" Bernstein said. "It is now demonstrable to all, for all to see, this is not a witch hunt. And if he tries to use Helsinki with Putin to once again claim that this is a witch hunt, as we heard in that setup, the idea somehow that the press or that the investigators are responsible for the horrors of undermining our elections in a way that has been shown definitively in what Rod Rosenstein laid out on Friday, that's part of the story."

CNN's Brian Stelter started the segment on his Sunday morning show warning how the truth "might not" come out of the meeting in Helsinki as Trump will meet with Putin privately for 90 minutes, without aides and note-takers in tow. After lamenting that "Trump simply cannot be trusted" and how political pundits will fill the "vacuum" by pundits, Stelter asked, "What should journalists do after he comes out of the Putin meeting and declares victory or something?"

Bernstein wasn't so pessimistic, noting how "this is a very porous White House" and there "has been great reporting that's been done out of this White House."

Bernstein also compared the situation to the Watergate scandal, which he reporting shed led on and led to President Richard Nixon's resignation in 1974.

"I think as in Watergate, a lot of the details are very hard to keep up with. Even for reporters," he said. "But I think more important, we have just seen, at the end of the week, on Friday, a tremendous development, which puts an end to the fiction that the president, that Republicans in Congress, that Fox, that others have promoted about a witch hunt."