WASHINGTON — (CNN) Hillary Clinton said Tuesday for the first time that she is “sorry” for using a personal email account while Secretary of State.

In an interview with ABC News for “World News Tonight with David Muir,” the Democratic presidential front-runner went further than ever before in accepting responsibility for the controversy and investigations that have dogged the early stages of her campaign. Clinton maintained a private email server that she used to conduct official business, which Republicans say put U.S. national security at risk.

“That was a mistake. I’m sorry about that. I take responsibility,” she said of her private account, according to excerpts from the interview released by ABC News.

The full interview with ABC will air later Tuesday.

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