ISIS insurgents released a video on Tuesday purportedly showing the beheading of U.S. journalist James Foley, who had gone missing in Syria nearly two years ago, and images of another U.S. journalist whose life they said depended on U.S. action in Iraq.The video, titled "A Message To America," was posted on social media sites. It was not immediately possible to verify its authenticity.Foley, who has reported in the Middle East for five years, was kidnapped on Nov. 22, 2012, by unidentified gunmen. Steven Sotloff, who appeared at the end of the video, went missing in northern Syria while he was reporting in July 2013.A Twitter account set up by his family to help find him said early on Wednesday: "We know that many of you are looking for confirmation or answers. Please be patient until we all have more information, and keep the Foleys in your thoughts and prayers."ISIS had not previously executed American citizens publicly. The video was posted after the United States resumed air strikes in Iraq for the first time since the end of the U.S. occupation in 2011.ISIS has declared a caliphate in parts of Iraq and Syria in areas it controls.The video opened with a clip of U.S. President Barack Obama saying he had authorised strikes in Iraq."Obama authorises military operations against the ISIS effectively placing America upon a slippery slope towards a new war front against Muslims," words appear in English and Arabic on the screen.It showed black and white aerial footage of air strikes with text saying "American aggression against the ISIS"A person identified as James Foley and wearing an orange outfit is seen kneeling in the desert as a man in black dress with a black mask stands beside him, holding a knife."I call on my friends family and loved ones to rise up against my real killers, the U.S. government, for what will happen to me is only a result of their complacency and criminality," the kneeling man says.The man in the mask speaks in a British accent and says: "This is James Wright Foley, an American citizen, of your country. As a government, you have been at the forefront of the aggression towards the ISIS.""Today your military air force is attacking us daily in Iraq. Your strikes have caused casualties amongst Muslims. You are no longer fighting an insurgency. We are an Islamic army, and a state that has been accepted by a large number of Muslims worldwide."Following his statement he beheads the kneeling man.At the end of the video, words on the side of the screen say "Steven Joel Sotloff" as another prisoner in an orange jumpsuit is shown on screen."The life of this American citizen, Obama, depends on your next decision," the masked man says.