The White House has said it is assessing the validity of a video purporting to show the murder of a US journalist by "Islamic State" militants. The group says it has beheaded the missing freelance reporter James Foley.
White House National Security Council spokeswoman Caitlin Hayden said the administration had seen the video and that its authenticity was being analyzed by intelligence officials.
"We have seen a video that purports to be the murder of US citizen James Foley…" deputy Hayden said. "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."
The release of the video came amid a United States airstrike campaign against "Islamic State" (IS) targets in Iraq.
The video opened with a clip of Obama saying he had authorized airstrikes in Iraq, with words appearing in English in Arabic. "Obama authorizes military operations against the Islamic State effectively placing America upon a slippery slope towards a new war front against Muslims," reads the text.
In the video, a person identified as James Foley is beheaded, before another man is shown in an orange jumpsuit, with the name "Steven Joel Sotloff" written onscreen. "The life of this American citizen, Obama, depends on your next decision," said a masked man in the video.
Following the release of the video, Foley's family tweeted an appeal for patience to well-wishers.
The 40-year-old Foley (pictured above), an experienced correspondent who had covered the war in Libya before heading to Syria, disappeared in November 2012 in the Syrian province of Idlib.
Sotloff, a reporter for several US newspapers and magazines, went missing while working in northern Syria in July 2013.
IS militants have declared a "caliphate" across swathes of Iraq and Syria, imposing a radically strict interpretation of Islamic law and signaling out religious minorities for persecution.
Earlier this week US jets targeted IS fighters on and around Iraq's largest dam - the Mosul Dam - allowing Kurdish Peshmerga and Iraqi forces to re-establish control over the vital piece of infrastructure. That operation represented the first major military setback for IS after a string of successes.
US fighter jets have also acted against IS militants advancing towards the Kurdish capital, Irbil, as well as jihadists posing a threat to Iraq's Yezidi minority.
rc/se (AFP, Reuters)