Hillary Clinton said Wednesday that the investigation regarding whether President Trump and his campaign colluded with Russia during the 2016 election could be bigger than the Watergate scandal.

"Do you think this is bigger than Watergate?" Anderson Cooper asked on CNN's "Anderson Cooper 360," referring to the Watergate scandal that led to President Richard Nixon's resignation in 1974.

"I think it's probably bigger than Watergate because it's about the future," Clinton responded.

Trump previously claimed that Clinton's email controversy was larger than Watergate when he was campaigning last October.

"This is bigger than Watergate. This is bigger than Watergate," he said. "In my opinion. This is bigger than Watergate."

Cooper also asked Clinton on Wednesday if she was convinced collusion existed.

"Let me say I'm convinced there was communication," she said. "I'm convinced there were meetings and phone calls. I'm convinced that there were financial entanglements. Let's wait to see what it's called. I'm convinced that there was something going on. Let's put the investigation to one side because, indeed, I have a lot of confidence in the special counsel."

Special counsel Robert Mueller and several congressional committees are investigating whether Russia attempted to influence the 2016 election and whether there are any connections between the Trump campaign and Russia.