The State Department admitted Wednesday that a 2013 press briefing video was purposefully altered to remove a portion of a discussion about the Iran nuclear talks, after an unknown State Department official asked that it be edited out.

Spokesman John Kirby's announcement contradicted the position held by the department for the last three weeks, during which officials said the video was missing because of a "glitch."

But Kirby said officials didn't know who asked for the video to be edited, and said the department is unlikely to investigate further into who wanted the video to be edited.

Kirby said he asked the Office of the Legal Adviser to look into the issue, and that officials "learned that a specific request was made to excise that portion of the briefing. We do not know who made the request to edit the video, or why it was made."

Kirby insisted that the person who made the edit only remembers that he or she got a call from someone at the State Department, who was passing on a request from the departments' Public Affairs Bureau. But he said the person who received the call didn't remember who the caller was, and doesn't know who in that bureau made the request.

The missing video clip was revealed more than three weeks ago, and it involves then-spokeswoman Jen Psaki, who was asked in 2013 whether officials ever lie to the public to protect national security interests. Psaki seemed to indicate that this does happen.

"James, I think there are times where diplomacy needs privacy in order to progress. This is a good example of that," Psaki replied to Fox News reporter James Rosen.

When it was revealed that the video had been edited to remove those comments, the State Department quickly restored the entire video, and blamed the missing video on a " glitch."

Psaki worked in the Public Affairs Bureau, but Kirby didn't say it was Psaki who made the request, or who it might have been. But he did say the request was made in 2013, when she was still at the State Department. She has since moved to the White House, and said Wednesday that she wasn't behind the decision to alter the video.

Rosen's question dealt with when the Obama administration started the Iran nuclear talks. The administration initially said the talks started in 2013, after moderate leaders took over Iran.

But evidence has since surfaced that the talks started earlier, before moderates were in power, a fact that some see as evidence that Obama wanted a deal at any cost.

Kirby said that while it was wrong to edit the video, there's no basis for investigating the issue further.

"There were no rules in place at the time to govern this sort of action, so while I believe it was an inappropriate step to take, I see little foundation for pressing forward with a formal investigation," he said.

The only forward-looking step the department is taking is to put rules in place to make it harder to alter videos in the future.

"To my surprise, the Bureau of Public Affairs did not have in place any rules governing this type of action," Kirby said. "Therefore, we are taking immediate steps to craft appropriate protocols on this issue, as we believe that deliberately removing a portion of the video was not and is not in keeping with the State Department's commitment to transparency and public accountability."