A portion of a US State Department briefing video that was archived online was deliberately deleted at the request of an unknown person, possibly the day the video was made, spokesman John Kirby said on Wednesday after an investigation.The deleted video segment dealt with whether a State Department spokeswoman had misled reporters at an earlier briefing about whether US and Iranian officials had directly discussed the Iran nuclear deal.Kirby said the office of the legal adviser "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.""To my surprise the Bureau of Public Affairs did not have in place any rules governing this type of action. 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," he added.Kirby said the video had been replaced some time ago with a full version that was archived with the Defense Department. He said the transcript of the briefing had always been available online and had not been modified.He said it was unclear why the video had been edited.