The State Department on Thursday released some 5,500 additional pages of emails sent and received by former secretary of state Hillary Rodham Clinton, but still failed to meet a court goal to make public most of her correspondence by year's end.
The State Department said it was putting out the information before the close of business on New Year's Eve, without complete information that makes the documents easily searchable as the government rushed to meet the deadline.
"We have worked diligently to come as close to the goal as possible, but with the large number of documents involved and the holiday schedule we have not met the goal this month," the State Department said in a statement. "To narrow that gap, the State Department will make another production of former Secretary Clinton's email sometime next week."
A court had ordered the department to release 82 per cent of Clinton's emails by the end of 2015. The State Department began making the emails public in May after revelations that Clinton had used a private server rather than a government account to send emails while serving as secretary of state.
Clinton, who is heavily favoured to win the Democratic Party's 2016 presidential nomination, has said using the private server was "a mistake," as the emails have become a liability in her presidential campaign, raising questions about transparency, technical security and the handling of sensitive email relating to the deadly 2012 attack on the US diplomatic compound in Benghazi, Libya.
Clinton's use of a private email server while secretary of state has continued to haunt her presidential campaign, reminding voters of the scandals and secrecy that often plagued her husband, Bill Clinton, during his 1993-2001 presidency.
The estimated 55,000-page email archive from Clinton's time as secretary of state is the subject of multiple lawsuits seeking their release under US open records laws.
The FBI is investigating Clinton's server to see if classified information was mishandled, while several newspapers and other media outlets as well as Republicans in Congress want to examine the emails, as her years of service come under the microscope of a presidential race.
The House committee investigating the Benghazi attacks said Thursday it was already reviewing the mails.