Hillary Clinton. Screenshot/Fox News Hillary Clinton claimed Sunday that FBI Director James Comey said statements she made about her use of a private email server as secretary of state "were truthful."

The remarks came in an interview with "Fox News Sunday" host Chris Wallace who challenged her on the claim.

The Fox host led into the question by playing three clips of answers Clinton gave about her use of the server in 2015, where she said she did not use the server to email classified material, that there was no classified email on the server, and that she was "confident" she never sent or received information marked classified at the time.

"After a long investigation, FBI Director James Comey said none of those things that you told the American public were true," Wallace said.

Clinton responded by saying "that's not what I heard" Comey say.

"Director Comey said that my answers were truthful and what I've said is consistent with what I have told the American people, that there were decisions discussed and made to classify retroactively certain of the emails," the Democratic nominee for president said.

She added: "I was communicating with over 300 people in my emailing. They certainly did not believe and had no reason to believe that what they were sending was classified. Now, in retrospect, different agencies come in and say, 'Well, it should have been." But that's not what was happening in real time.'"

Wallace then cited Comey's hearing in front of the House Committee on Oversight and Government Reform from earlier this month, where he said Clinton's prior statements that there was "nothing marked classified on her emails, either sent or received" and that "there is not classified material" weren't accurate.

"He not only directly contradicted what you said, [he] also said in that hearing that you were extremely careless and negligent," Wallace said.

Clinton replied, acknowledging that she "made a mistake" by "not using two different email addresses."

"I have said that, and I repeat it again today. It is certainly not anything that I ever would do again," she said. "I take classification seriously."