The new video comes around two weeks after another American journalist James Foley was beheaded by ISIS. Reportedly, the US intelligence officials are working to determine the video's authenticity.
Follow the updates here:
3:00 pm: US intelligence confirms authenticity of video of execution of Steven Sotloff.
2:50 pm: "We will not be intimidated. We will only be united", said Obama on journalist Steven Sotloff's beheading by Islamic state militants.
12:51 pm: According to New York Times, ISIS said it killed Steven Sotloff after US strikes in Northern Iraq.
11:00 am: Al Jazeera appealed to all media organisations to not show any images of beheading of Steven on their websites or social media pages.
10:00 am: President Barack Obama approved assigning 350 additional troops to protect the U.S. Embassy in Baghdad.
9:40 am: UN chief Ban Ki-Moon outraged at Journalist beheading, calls for tolerance, mutual respect and non violence.
9:00 am: "We are sickened by this brutal act", said State Department spokeswoman Jen Psaki.