By law, the records can be withheld from public scrutiny for up to 12 years after a president leaves office unless there is an assertion of presidential privilege by either the past or current president. It's not clear who or what caused the delay. Unlike other presidential libraries, the withheld Clinton material is under the control of the federal government.
A White House aide said Tuesday President Obama had cleared about 25,000 pages and that they should be released soon.
Chris Isleib, director of communications for the National Archives, said the agency's goal was to release the documents as quickly as possible, but additional time would be required "to complete the logistics of making available such a large release."
An aide to former president Clinton said, "President Clinton did not intend to assert privilege with respect to the documents."
Information posted online by the National Archives indicated many of the withheld documents originated in Hillary Clinton's office. Those documents assume greater importance as the former first lady and secretary of state is considered the front-runner for the 2016 Democratic presidential nomination.