The militant group calling itself the Islamic State has released a video purporting to show the beheading of American journalist Stephen Sotloff.
In the video, Sotloff describes himself as “paying a price” for US intervention in Iraq.
White House spokesman Josh Earnest told reporters in a briefing that if there is such a video it would be analysed very carefully by the US government and intelligence officials to determine its authenticity.
Earnest added that the Obama administration’s thoughts and prayers were with Sotloff’s family.
A masked figure in the video also issued a threat against a British hostage, a man the group named as David Haines, and warned governments to back off “this evil alliance of America against the Islamist State,” according to the SITE intelligence group which monitors jihadist organisations.