Likely Democratic presidential candidate Hillary Clinton said on 10 March it would have been better if she had used a government email account and a separate mobile device as US secretary of state, but said the vast majority of her correspondence went to employees using government addresses.

Clinton has come under fire for her use of a private email account for official business when she served as the top US diplomat because of concerns about security and concerns that she shielded important facts about her tenure from the public.

"I opted for convenience to use my personal email account, which was allowed by the State Department, because I thought it would be easier to carry just one device for my work and for my personal emails instead of two," Clinton told reporters during a press conference at the United Nations in New York in an effort to defuse the controversy over her use of a single mobile device and a private email account.

"Looking back, it would've been better if I'd simply used a second email account and carried a second phone, but at the time, this didn't seem like an issue," she added.

Clinton, the presumed front-runner for the 2016 Democratic presidential nomination, said she had provided to the State Department all of her emails that could possibly be work related for archiving purposes.

"In going through the e-mails, there were over 60,000 in total, sent and received. About half were work-related and went to the State Department and about half were personal that were not in any way related to my work. I had no reason to save them, but that was my decision because the federal guidelines are clear and the State Department request was clear," said Clinton.

She said she chose not to keep personal emails on topics such as her daughter's wedding.

Clinton said that her emails sent to government addresses had been automatically preserved.

"I did not email any classified material to anyone on my email. There is no classified material," said Clinton.

Clinton tried to head off criticism last week by urging the State Department to quickly review and release her emails.

That was not enough to placate Republicans, who have questioned her transparency and ethics, and some Democrats, who are wary that the party's front-runner for the 2016 White House race could be tarnished.

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