A planned appearance by Brian Williams on the Late Show with David Letterman scheduled for Thursday night has been cancelled amid backlash over his “misremembered” stories about Iraq and Hurricane Katrina. Despite an NBC News source speaking with Howard Kurtz at Fox News about Williams considering using the Thursday night appearance to clear the air, NBC has now reported that he will not appear on the show.

Sunday’s news about the Letterman cancellation comes the day after Williams announced that he will be stepping away from his anchor spot on NBC’s Nightly News for a few days as the network investigates his admission that his story about being on a helicopter that was hit by a grenade in Iraq in 2003 was false. On a previous Late Show interview with Letterman, Williams had continued to spread the helicopter story. As recently as March 2013 Williams told Letterman the story about his helicopter being hit by RPG fire.

Williams had been scheduled for the Thursday Late Show appearance before his apparently false stories came to light last week. Last week, Williams apologized on air for telling an inaccurate story about his coverage of the invasion of Iraq.

In stepping away from the anchor chair, Williams stated that it had become “painfully apparent” to him that he is presently too much a part of the news to make him effective in reporting it. Lester Holt will be sitting in the anchor chair in Williams’ place. Williams has not been specific about when he would return.