A VIDEO has been released online by ISIS militants that purports to show the Jordanian pilot Muath al-Kasaesbeh being burned to death.
The video, published through official ISIS media channels, shows a man in an orange jumpsuit standing upright in a cage. A burning torch is then held to a trail of oil leading to the cage before the man appears to be set alight.
A spokesman for the Jordan army has confirmed the death of Muath al-Kasaesbeh and said that the 26-year-old pilot was killed a month ago.
Lt Kasaesbeh's family have been informed of the development by the Jordanian armed forces.
The video, which is yet to be authenticated, represents a departure from previous methods of execution used by Isis.
A spokesperson for the White House National Security Council said the US was aware of the video and was working to confirm its authenticity.
"The United States strongly condemns ISIL's actions and we call for the immediate release of all those held captive by ISIL," they said, using another acronym to describe the Isis group.
"We stand in solidarity with the Government of Jordan and the Jordanian people."
President Obama said the video is another indication of the "viciousness and barbarity" of the organisation.
He added that if the video is confirmed as genuine, it would "re-double the determination" of the global coalition to destroy Isis.
UK prime minister David Cameron has issued a statement. He said: "Lieutenant Moaz al-Kasasbeh's sickening murder will only strengthen our resolve to defeat ISIL. My prayers are with his family tonight."
The spokesman for the Jordanian armed forces vowed "punishment and revenge" in a statement read on Jordanian TV.
Mamdouh al-Ameri said: "The military forces announce that the hero pilot, Muath al-Kaseasbeh, has fallen as a martyr, and ask God to accept him with the martyrs.
"While the military forces mourn the martyr, they emphasize his blood will not be shed in vain.
"Our punishment and revenge will be as huge as the loss of the Jordanians."
In January, Jordan reportedly threatened to expedite the trials of prisoners affiliated with Isis, some of whom may face the death penalty, if the group killed Lt Kasaesbeh.
A government spokesman, Mohammed al-Momani, previously said that the authorities were "ready to hand over the convict Sajida al-Rishawi in return for the return of our son and our hero".
A source in Amman has since told a CBC reporter that Jordan authorities have moved the Iraqi woman offered in a prisoner exchange to a prison where death sentences are carried out.