The video purporting to show US journalist Steven Sotloff being executed is authentic, the White House said on Wednesday.
“The US Intelligence Community has analysed the recently released video showing US citizen Steven Sotloff and has reached the judgment that it is authentic,” said National Security Council spokesperson Caitlin Hayden.
The video showing the beheading of the journalist was released by the Islamic State group on Tuesday, which called it retribution for continued US airstrikes in Iraq.
Sotloff, 31, who freelanced for Time and Foreign Policy magazines, had last been seen in Syria in August 2013 until he appeared in a video released last month that showed the beheading of fellow American journalist James Foley.
Dressed in an orange jumpsuit against the backdrop of an arid Syrian landscape, Sotloff was threatened in that video with death unless the US stopped airstrikes on IS group in Iraq.
In the video distributed on Tuesday and entitled “A Second Message to America,” Sotloff appears in a similar jumpsuit before he was purportedly beheaded by an Islamic State fighter.
Watch: Sotloff’s mother pleaded for her son's release
Authenticity of the video could not be immediately verified. The SITE Intelligence Group, a US terrorism watchdog, first reported about the video’s existence.
The fighter who beheads Sotloff in the video called it retribution for Obama’s continued airstrikes against the group in Iraq.
“I’m back, Obama, and I’m back because of your arrogant foreign policy towards the Islamic State ... despite our serious warnings,” the fighter said.
At the end of the video, he threatened to kill a third captive, a Briton, David Cathorne Haines.
Sotloff’s mother had pleaded for his release last week in a video directed at the Islamic State group.
Addressing the leader of the Islamic State group by name, Shirley Sotloff said in a video that her son was “an innocent journalist” who shouldn’t pay for US government actions in the Middle East over which he has no control.
Watch: US reacts to alleged beheading of 2nd US journalist by IS