The State Department is currently reviewing some 55,000 pages of emails which were turned over to it by personal staff of Clinton, the Washington Post reported.
Officials, however, have not said how long they would take in reviewing these emails.
"We are not going to prejudge the outcome of the review of Secretary Clinton's 55,000 pages of e-mails," a State Department official was quoted as saying.
A day earlier, State Department Deputy Spokesperson Marie Harf said that the agency would try to do it as soon as possible but this might take time.
"We are now in the process of appropriately reviewing those for public release, as we do for any document for public release. And we will undertake this task as rapidly as possible in order to make sure that we're dealing with the sheer volume of this in a responsible way and we'll conclude it as soon as we can and get those released publicly," Secretary of State John Kerry told reporters in Riyadh.
Kerry is the first Secretary of State, who is using official State Department email.
Clinton in a tweet late Wednesday night had said she has asked the State Department to make these emails public as soon as possible.
The Washington Post said the controversy has created a new political complication for Clinton, a possible Democratic front-runner for president, with some Democrats expressing concern that her penchant for secrecy could become a weakness in the general election next year.
According to Buzzfeed, even as Clinton has handed over 55,000 pages of her emails to the State Department, an undisclosed number of pages from the email account that Clinton used exclusively during her four-year tenure as secretary will remain private.
Clinton's use of personal email while serving as secretary of state raises serious questions about transparency and accountability, said The Sunlight Foundation, a non-profit organisation.
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