"The intelligence community is working as quickly as possible to determine its authenticity," Hayden noted, adding "If genuine, we are appalled by the brutal murder of an innocent American journalist and we express our deepest condolences to his family and friends."
Earlier Tuesday, a four-minute video entitled "A Message to #America (from the #Islamic State) was posted to YouTube, apparently showing the execution of American journalist James Wright Foley for America's military action in Iraq, and warning that U.S. involvement in Iraq will determine whether another captive, American journalist Steven Joel Sotloff, will live or die.
Editor's note: UPI will not reproduce, in part or in whole, the video posted by IS. This is out of respect to the Foley family and because the video constitutes propaganda for a group designated as terrorist organization by several countries, including the United States.
Notable deaths of 2014 [PHOTOS]
Boko Haram leader says in video he's still alive