Supporters take part in a candle light vigil at the University of Central Florida, Sept. 3, 2014, in Orlando, Fla., to honor Steven Sotloff, a UCF former student and the second American journalist to be beheaded by the Islamic State group in two weeks.

Supporters take part in a candle light vigil at the University of Central Florida, Sept. 3, 2014, in Orlando, Fla., to honor Steven Sotloff, a UCF former student and the second American journalist to be beheaded by the Islamic State group in two weeks. John Raoux/AP

Islamic State Militant Beheads U.S. Journalist Steven Sotloff in Video, Group Says

As they warned they would, Islamic State fighters beheaded American Steven Sotloff, says intel group. By Kevin Baron

This story has been updated.

American journalist Steven Sotloff has been executed and beheaded by the Islamic State group, according to a new video posted on Monday. 

The killing fulfills the Islamic State’s threat to President Barack Obama that Sotloff also would be killed as journalist Jim Foley was two weeks ago unless the U.S. ceased air strikes against them.

“I am Steven Joel Sotloff. I'm sure you know exactly who I am by now and why I am appearing before you,” he says, according to a transcript posted by SITE Intelligence Group, which has posted a still photo and portions of a video showing Sotloff on his knees in an orange jumpsuit next to a masked Islamic State fighter. The video is cut short before Sotloff's execution. 

“The United States, as you know, has dedicated significant time and resources to try and rescue Mr. Sotloff,” said White House spokesman Josh Earnest, who sent the president’s thoughts and prayers to the Sotloff family in a short statement in the briefing room, and promised the U.S. would analyze the video closely.

According to SITE Intelligence group, in the new video the same executioner of Foley says, “I'm back, Obama, and I'm back because of your arrogant foreign policy towards the Islamic State, because of your insistence on continuing your bombings and [unclear] on Mosul Dam, despite our serious warnings. You, Obama, have but to gain from your actions but another American citizen. So just as your missiles continue to strike our people, our knife will continue to strike the necks of your people.”

U.S. officials appeared surprised by the video's Monday release. "If the video is genuine, we are sickened by this brutal act taking the life of another innocent American citizen. Our hearts go out to the Sotloff family," said State Department spokeswoman Jen Psaki.

"Just like you, we’re trying to find out ground truths here," said Pentagon press secretary Rear Adm. John Kirby, declining to offer further details about it's timing or authenticity.