Sotloff, who disappeared in Syria in 2013, also appeared in another video released by the Islamic State of Iraq and al-Sham (ISIS) last month, which showed the decapitation of American journalist James Foley.
“The U.S. Intelligence Community has analyzed the recently released video showing U.S. citizen Steven Sotloff and has reached the judgment that it is authentic. We will continue to provide updates as they are available,” National Security Council Spokesperson Caitlin Hayden said early Wednesday, in emailed comments.
On Tuesday, President Obama addressed the video, vowing to “degrade and destroy” ISIS, adding that justice will be served for the barbaric killings.
“We will not be intimidated,” Obama told reporters during a visit to Estonia on Wednesday. “Those who make the mistake of harming Americans will learn that we will not forget and that our reach is long and that justice will be served.”
He also vowed that the U.S. would continue to lead the battle against “the kind of barbaric and empty vision that [ISIS] represents.” He said that mission would “take some time but it is going to get done,” adding: “We will degrade and destroy [ISIS] so that it is no longer a threat to Iraq, the region and United States.”
The president said that Sotloff “deeply loved the Islamic world” and had risked his life traveling in the Middle East to “tell the story of Muslim men and women demanding dignity.” He added: “Steven’s life stood in sharp contrast to those that murdered him so brutally.”
Watch Obama’s ISIS address in the video above. We’ll keep you updated with the latest.