The Islamic State of Iraq and the Levant has released a new video purportedly showing the decapitation of British aid worker Alan Henning. After Henning's execution, ISIL threatened to execute an American aid worker.

According to the SITE Monitoring Service, ISIL released the 1-minute 11-second video on Friday. Titled "Another Message to American and its Allies," the video shows Henning kneeling on a desert landscape with an ISIL operative wearing all black. The set-up repeats those seen in previous execution videos.

"I'm Alan Henning," said Henning at the beginning of the video. "Because of our Parliament's decision to attack the Islamic State, I, as a member of the British public, will now pay the price for that decision."

The video then cuts to the ISIL executioner, believed to be the same one from the previous videos.

"The blood of David Haines was on your hands [British Prime Minister David] Cameron," said the mask ISIL fighter, referring to the beheading of another British aid worker. "Alan Henning will also be slaughtered, but his blood is on the hands of the British Parliament."

Following Henning's execution, the masked man revealed another hostage identified as Peter Edward Kassig, an American aid worker.

"Obama, you have started your aerial bombardment of Sham [Syria], which keeps on striking our people," the man said. "So it is only right that we continue to strike the necks of your people."

Kassig is an Army Rangers veteran who served in Iraq from 2006 to 2007, according to the Washington Post. Following his discharge from the Army, he founded a humanitarian aid organization called Special Emergency Response and Assistance, or SERA, and it was based near the Turkey-Syria border.

The White House released a statement condemning Henning's execution and saying the U.S. will work with its allies to bring to justice his killer.

"The United States strongly condemns the brutal murder of United Kingdom citizen Alan Henning by the terrorist group ISIL," the statement said, praising Henning's humanitarian work and lamenting his family's loss.

"Standing together with our U.K. friends and allies," the statement continued. "We will work to bring the perpetrators of Alan's murder ... to justice."

The British government also responded to Henning's execution, according to The Guardian.

"We are aware of the video and are working urgently to verify the contents. If true, this is a further disgusting murder. We are offering the family every support possible; they ask to be left alone at this time," said a U.K. Foreign Office spokesman.

David Cameron also expressed his disgust at ISIL's actions and remembered Henning's humanitarian work in Syria.

"The brutal murder of Alan Henning by Isil [Isis] shows just how barbaric and repulsive these terrorists are. My thoughts and prayers tonight are with Alan's wife Barbara, their children and all those who loved him," Cameron said.