Humanitarian Alan Henning has been beheaded by terrorist group ISIS, confirmed by another video purporting to show the grisly footage which emerged online Friday.

ISIS released another short video showing the beheading of British Aid worker Henning. In what has become a familiar sight, the victim is dressed in a bright orange jumpsuit with his captors behind him, covered up and waving a knife around.

Prior to the beheading, Henning speaks to the camera about the British Parliament's decision to join America in the bombing campaign against ISIS.

After the brutal beheading, the camera shifts to American Peter Kassig, who ISIS threatens to kill next.

Henning was part of a group of volunteers that traveled to Syria in December 2013 to help bring food and water to those affected by the civil war. He was captured by masked gunmen just after Christmas.

After the video went live, Prime Minister David Cameron vowed to bring the killers to justice and stated: "The brutal murder of Alan Henning by ISIL shows just how barbaric and repulsive these terrorists are. Alan had gone to Syria to help get aid to people of all faiths in their hour of need. The fact that he was taken hostage when trying to help others and now murdered demonstrates that there are no limits to the depravity of these ISIL terrorists."

The White House also released a statement after Henning's death: "Mr. Henning worked to help improve the lives of the Syrian people and his death is a great loss for them, for his family and the people of the United Kingdom.

"Standing together with our UK friends and allies, we will work to bring the perpetrators of Alan's murder -- as well as the murders of Jim Foley, Steven Sotloff and David Haines -- to justice. Standing together with a broad coalition of allies and partners, we will continue taking decisive action to degrade and ultimately destroy ISIL."