NEW YORK (Reuters) - The U.S. State Department asked a judge on Friday for a one-month extension to finish publicly releasing thousands of emails sent by Democratic presidential candidate Hillary Clinton while she was secretary of state, in part because a winter storm closed government offices.

The department said in a federal court filing it needed until Feb. 29 after realizing this week that it had “overlooked” emails amounting to 7,254 printed pages that it should have already shared with other agencies for them to review for sensitive information.

It said expected heavy snow in Washington, D.C., had interrupted delivery of these emails to other agencies. Many federal offices closed early on Friday afternoon.

In a statement, Mark Toner, a department spokesman, said “the remaining emails are also the most complex to process as they contain a large amount of material that required interagency review.” He said the department would release as many emails “as possible” on Jan. 29, the original deadline ordered by the court.

Clinton, the front-runner for the Democratic presidential nomination, sent and received email on a private server in her home between 2009 and 2013, but this arrangement did not become public until early 2015.

The revelation has dogged her campaign. Republicans and other critics say she was skirting transparency laws and endangered sensitive government information. Clinton says she did nothing wrong.

After a government inspector general raised concerns that classified information may be outside government control, the Federal Bureau of Investigation took the server and other equipment from at least two private technology firms that managed Clinton’s systems for examination.

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A little more than 80 percent of the roughly 30,000 work emails Clinton returned to the State Department in 2014 have now been made public after Jason Leopold, a VICE News reporter, sued the department under freedom of information laws.

More than 1,300 of those emails have been partly redacted in the public release because the State Department says they contain classified information.

Ryan James, Leopold’s lawyer, said he would “vigorously oppose” an extension.

“I think it is fair to ask how many more extensions is State going to seek and what’s in the remaining emails that requires so much more time to review and release them?” James wrote in an email.

Spokesmen for Clinton did not respond to a request for comment.

Whether District Court Judge Rudolph Contreras will grant the extension is unclear, but if he does it will push the release back until after the casting of votes in Iowa, New Hampshire, Nevada and South Carolina, the first four states in the presidential nominating process.