Donald Trump said in a new interview that the scandal over Hillary Clinton's private email server is "one of the worst things" he's ever seen.

"Well, I'm worried about her getting it [classified information] because of her email situation," Trump said in an interview ahead of his Wisconsin rally Tuesday night with Fox News that aired Wednesday morning. "She can't keep anything private."

"She deleted 33,000 emails, which is a crime. What she did is a crime," Trump added. "It's unthinkable."

Trump is scheduled to received his first intelligence briefing on Wednesday. Clinton will also receive her first one as the Democratic presidential nominee soon.

"And I think probably the single greatest achievement in her life will be getting out of that mess — and I don't think she's really out of it," Trump said. "I can't believe that she's out of it. Justice has to be ashamed. When you look at the fact that she did so many things wrong."

Trump said it is "hard to believe" that "Crooked Hillary" got away with "the volume of things she did wrong."