Carl Bernstein warns Trump has caused a ‘genuine national security crisis’ for America
Carl Bernstein on CNN (screengrab)

Pulitzer Prize-winning investigative journalist Carl Bernstein warned America is experiencing a "genuine national security crisis" with Donald Trump continuing to serve as president.

Bernstein's Washington Post investigation of Watergate, with Bob Woodward, helped cause the resignation of President Richard Nixon. The two then wrote the 1974 non-fiction book All the President's Men which was adapted into a movie of the same name starring Dustin Hoffman as Bernstein and Robert Redford as Woodward.

The journalist was interviewed on Saturday by CNN's Wolf Blitzer.

"I think there are two things going on at once, both of grave consequence to the country at a very perilous time," Bernstein explained.

"The first is a very serious impeachment inquiry based on preliminary evidence that really suggests that the president himself has compromised the national security of the United States. That he has collaborated with a foreign power to try and obtain dirt on a political opponent -- something that’s never happened in our history in this manner from a foreign power," he explained.

"But the other thing that’s going on right now is we are in a genuine national security crisis because -- and it may be even more consequence though it is connected to the impeachment in some ways than the impeachment, itself -- because for the first time in our history we also have a president of the United States about whom we now have serious suggestions, may not be capable or willing or able or knowledgeable enough to protect and defend the United States against enemies, foreign -- foreign powers," he continued.

"It is essential that those papers, those conversations, those digitalized memos in the so-called 'locked box' be examined by some people at the highest levels of the executive branch of our government to determine whether or not this president has undermined our national security," he explained.

"And very quickly, because it is a real crisis," Bernstein added.