The Democratic presidential front-runner said in an interview with NBC News that she was immediately confronted by a number of global hotspots after joining the new Obama administration as its top diplomat and didn't think much about her email after arriving at her new job.
"You know, I was not thinking a lot when I got in. There was so much work to be done. We had so many problems around the world," Clinton said. "I didn't really stop and think what kind of email system will there be?"
But Clinton did not apologize for her decision when asked directly, "Are you sorry?" Instead, she again said she wishes she had "made a different choice" and that she takes responsibility for the decision to use a private email account and server based at her home in suburban New York.
She added it was a choice that should not raise questions about her judgment.
"I am very confident that by the time this campaign has run its course, people will know that what I've been saying is accurate," Clinton said, adding: "They may disagree, as I now disagree, with the choice that I made. But the facts that I have put forth have remained the same."
Republicans criticized Clinton's unwillingness to apologize for the decision and said it underscored polls which have shown large numbers of people questioning her trustworthiness. "What's clear is Hillary Clinton regrets that she got caught and is paying a political price, not the fact her secret email server put our national security at risk," said Michael Short, a spokesman for the Republican National Committee.
The conversation about emails led off a wide-ranging interview that included Vice President Joe Biden's interest in a potential Democratic primary bid, Clinton's plans to address the Iran nuclear deal and her views of Republican front-runner Donald Trump.
Following a summer in which both Trump and Vermont Sen. Bernie Sanders, Clinton's chief rival for the Democratic nomination, drew large campaign audiences, Clinton sought to cast her candidacy as one rooted in tackling the problems "that keep families up at night."
"Because I think you can come with your own ideas and you can, you know, wave your arms and give a speech, but at the end of the day, are you connecting with and really hearing what people are either saying to you or wishing that you would say to them?" she said.
Sanders campaign spokesman Michael Briggs responded: "Bernie is doing more than attracting large crowds. He has a concrete set of proposals to take on the billionaire class and rebuild the disappearing middle class. That's what people are responding to."
Clinton's interview comes as current and former aides are testifying before a congressional panel investigating the deadly 2012 Benghazi attacks. The committee has also delved into Clinton's email practices at the State Department. She is scheduled to testify publicly before the panel next month.
Clinton in August handed over to the FBI her private server, which she used to send, receive and store emails during her four years as secretary of state. Clinton has said she set up her own system instead of using a State Department account for the convenience of using a single Blackberry device.
But her comments that she didn't stop to think about setting up a private email server in her home belied the careful planning and technical sophistication required to set up, operate, maintain and protect a private server effectively — especially one responsible for the confidential communications of the U.S. government's top diplomat as she traveled the globe.
Even homebrew servers typically require careful configuration, Internet registration, data backups, regular security audits and a secondary power supply in case of electrical problems.
In the interview, Clinton said, as she has in the past, that she "should have had two accounts, one for personal and one for work-related."
Thousands of pages of her emails publicly released in recent months have shown that Clinton received messages that were later determined to contain classified information, including some that contained material regarding the production and dissemination of U.S. intelligence.
But Clinton reiterated that she did not "send or receive any material marked classified. We dealt with classified material on a totally different system. I dealt with it in person."
Clinton also addressed other topics, including:
— Iran: Clinton noted her support for an Obama-backed agreement to curb Iran's nuclear ambitions and said she would address what she would do as president to enforce the deal, hold Iran accountable and "make clear that no options were off the table. That they can never ever have a nuclear weapon."
—Trump: Clinton suggested that Trump, the leading GOP candidate at this juncture, did not have the temperament to lead the nation and conduct foreign policy. "Loose talk, threats, insults, they have consequences. So I'm going to conduct myself as I believe is appropriate for someone seeking the highest office in our country," she said.
—Biden: Clinton declined to offer a comparison to the vice president and fellow Democrat, saying he had a "really difficult decision" to make.