ISIS militants released brutal video footage this afternoon of the beheading of a kidnapped American photojournalist as a warning to the United States to stop intervening in Iraq.

The video of the beheading of American photojournalist James Wright Foley is extremely graphic, and has been making waves across news channels since it surfaced.

A YouTube video and photos purportedly of Foley emerged on Tuesday. The video -- entitled "A Message to #America (from the #IslamicState)" -- identified a man on his knees as "James Wright Foley," and showed his beheading.

"This is James Wright Foley, an American citizen of your country," an Islamic State militant says in the video, which has since been removed by YouTube. "As a government, you have been at the forefront of the aggression towards the Islamic State. You have plotted against us and have gone far out of your way to find reasons to interfere in our affairs. Today, your military air force is attacking us daily in Iraq, your strikes have caused casualties among Muslims."

Foley, a 40 year old freelance photojournalist who contributed to the Global Post, was first captured in Libya in 2012. He was later released, and then kidnapped again around Thanksgiving 2012 by unidentified gunmen in Syria.

The Global Post originally kept Foley's kidnapping in Syria quiet out of fear for his safety, but eventually reported the circumstances behind his disappearance.

According to their reports, Foley had set off toward the border in Syria in a car about an hour before his capture. According to witnesses, an unmarked car intercepted Foley, and men holding kalashnikovs shot into the air to force Jim out of the car.

According to the witness, there was nothing to indicate whether the aggressors were rebel fighters, kidnappers seeking a ransom, pro-government militia members, or members of a religious-based group. Foley was held captive for 635 days before his beheading.

The video also shows another man on his knees, who is identified as American journalist Steven Sotloff. The Islamic State member says that Sotloff's future "depends" on President Obama's "next decision." Sotloff, a freelance journalist, went missing in Syria last August.