Last month the group killed James Foley and it’s believed the murder of Steven was committed by the same individual.
The horrifying footage shows Steven, kneeling before the front of his murderers, before he is beheaded.
READ: BRITISH MUSLIMS VOW TO HELP CATCH JAMES FOLEY'S KILLERS
Their deaths are what IS claim is punishment for US airstrikes in Iraq, where the militant group have been accused of ethnic cleansing.
Earlier this evening, a White House press secretary spoke about the video and offered their wishes to Steven’s family.
“This is something that the administration has obviously watching very carefully since this threat against Mr Sotloff’s life was originally made a few weeks ago. Our thoughts and prayers, first and foremost, are with Mr Sotloff and Mr Sotloff’s family and those who worked with him.”
Last week, we reported how Muslim community leaders in the UK had pledged their support in tracking down the killer of James Foley, who is believed to be British.
Mohammed Shafiq, from the British Ramadhan Foundation, said they would help in every way they could.
“As Muslims we reject terrorism and the evil IS [Islamic State] – they do not act in our name and we abhor anyone who supports them,’ he told Metro.
“We stand ready to support the police and intelligence agencies in their work to defeat terrorism and protect our nation.”
The Muslim Council of Britain added: ‘We condemn unreservedly their psychopathic violence, whether it is on minorities, on civilians, or on fellow Muslims.”
You may also be interested in: Man brutally attacked for likeness to reality star