Journalist Bob Woodward on Sunday warned against labeling President Trump's firing of FBI Director James Comey as a crime or treacherous move to hamper the agency's investigation into potential ties between Trump's campaign and Russia.

"This is not yet Watergate — not yet a clear crime," said the Pulitzer Prize-winning reporter who helped report the Watergate scandal that led to the resignation of President Richard Nixon in 1974. He was participating in a panel on "Fox News Sunday."

Woodward added that Trump's actions since launching his campaign have long been "strange and unpredictable and impulsive."

"But in the case of Nixon, he had his former White House counsel John Dean for four days testifying that the president corruptly and illegally led the obstruction of justice. And you have nothing comparable," Woodward said. "Now that doesn't mean, you know, we don't know where this is gonna go there is a tremendous amount of smoke."

"There are, you know, a thousand questions and they should be answered, but there's no evidence President Trump at this point will somehow involve in collusion here, that's an important," Woodward said.