State Department officials are delaying the publication of hundreds of Hillary Clinton's private emails until Saturday because the emails must be shifted off the classified system where they must be stored.

After missing a court-ordered deadline to post the remaining batch of Clinton's emails online by the end of January, the State Department faced pressure from a federal judge to roll out some of the emails throughout February rather than wait until the end of the month.

State Department officials argued in federal court that the process of posting emails on its Freedom of Information Act website was so burdensome that they might need to delay until Feb. 29 to publish the final batch of records.

But Judge Rudolph Contreras, who is overseeing the contentious FOIA lawsuit, was not satisfied with that answer and asked the agency in a hearing Monday to publish an interim trove of emails by Feb. 18.

"[T]he total amount of time required for the team to complete the posting of the interim production could be upwards of 16 hours, approximately two 8-hour days," officials argued in documents that pushed the court to allow them more time to publish 550 Clinton emails slated for release Saturday.

The agency refused to describe the process by which officials must move the emails from a classified environment to an unclassified network because even that process is too sensitive to share with the public.

"The specific details of how this is accomplished implicate systems security concerns, and are not appropriate for discussion in a public filing," agency officials wrote.

Although the State Department said in Wednesday's filings the agency had dedicated substantial resources to the review of Clinton's emails, officials said the "extremely rigid and slow" computer system could cause the staff further delays.

"This process, which cannot be automated, starts with the manual, document-by-document process of removing internal markings that are used for tracking purposes during the review process," officials said of the system of publishing the emails online. "It could take anywhere from two to four hours to complete this task for the documents that are the subject of this declaration, depending on the availability of staff to do this work."

A major part of the delay, according to the court documents, can be attributed to the fact that all 55,000 pages of Clinton's emails must be kept on a classified system until they are properly redacted and can be transferred to an unclassified system.

Clinton has repeatedly argued that nothing she sent or received was marked classified at the time.

However, the highly sensitive nature of more than 1,600 emails has forced the agency to take additional steps to protect the records as officials sift through them ahead of their release.

State officials offered to print the 550 emails and hand them over to Jason Leopold, the Vice News reporter who filed the FOIA request, by Friday instead of stalling the public release of the emails until Saturday.

The latest delay occurred in mid-January after State Department staff discovered more than 7,000 pages of emails that had not yet been sent to outside agencies for review.

Since then, those agencies have returned more than 1,000 pages to the State Department, officials said.

Their attempt to delay the final release of Clinton's emails until the end of Feb. after agreeing last summer to put all the documents out by January has been criticized as a move meant to shield Clinton as she weathers difficult primaries and caucuses this month.

Both the State Department and the White House has denied the move had any political motivations.