Washington ( CNN ) -- Is a jihadist featured on a 55-minute video released by ISIS , warning the United States against getting in its way in Iraq and Syria , an American ? That 's the question being asked by U.S. intelligence officials as they analyze a recruitment video that features the jihadist , who speaks perfect English with a North American accent , orchestrating a mass execution . The United States is doing a voice analysis and comparing what it finds to people the intelligence community has been watching , the officials told CNN on Saturday . The analysis is in its initial stages , according to the officials . Officials see the killer 's appearance in the video as significant because he comes across , they say , as articulate and persuasive -- a person of influence within the terror group . In the video titled `` Flames of War , '' the jihadist first appears speaking Arabic in a classical dialect and with the ease of a native Arabic speaker , CNN terrorism analyst Paul Cruickshank said . But the ISIS fighter -- who is masked and wearing a camouflage uniform -- seamlessly switches to English . There are a number of men digging a ditch behind him . The jihadist claims they are Syrian soldiers assigned to a 17th Division military base near the Syrian city of Raqqa , and who now , after an ISIS attack , are `` digging their own graves in the very place where they were stationed . '' CNN can not independently verify that the men in the video were soldiers , as the propaganda video claims . How the 'Islamic State ' is run , from oil to beheadings . The video then shows the speaker and a group of militants executing the men , who fall into the ditch . The man who led this atrocity on film could be an Arab who was educated in the West . Or he could be an American or Canadian . If so , Cruickshank said , he would be the first North American jihadist to commit a war crime on camera . `` Clearly ISIS had a calculated step to be able to put this guy on camera , '' said Frank Cilluffo , a security analyst at George Washington University . `` Why ? Because he seems American . The message is aimed at a Western audience . '' The difference between ISIS and al Qaeda . ISIS , ISIL or the Islamic state ? CNN 's Brian Todd contributed to this report .
U.S. intelligence officials are analyzing the voice on a ISIS video . They are comparing it with the voices of officials being watched , officials from Syria . The 55-minute video released by ISIS shows the jihadist leading a mass execution . In the video , he speaks first in Arabic , then in English .