United States President Barack Obama has criticized the beheading of U.S. aid worker Abdul-Rahman Kassig saying that it was 'an act of pure evil' by Islamic State (IS) militants.
Meanwhile, IS militants released a video claiming to have executed Kassig as a warning to the U.S.
In the 16 minute long video, a black clad militant standing before a severed head claimed that the man was Kassig.
Kassig's parents said that he died as a result of his love for Syrian people.
Obama also said that Kassig who was taken while working for a refugee group, was a humanitarian.