The video shows a man standing in a cage and engulfed in flames. Intelligence officials are working to confirm it is genuine.
Jordan vowed “punishment and revenge”.
Lt Kasasbeh was captured when his plane came down near Raqqa, Syria, in December on a mission to support the US-led military coalition against IS.
The video posted online on Tuesday was distributed via a Twitter account known as a source for IS propaganda. Jordanian state TV reports that Lt Kasasbeh, 26, was killed a month ago.
The highly produced 22-minute film includes a sequence showing the Jordanian pilot walking at gunpoint amongst rubble apparently caused by coalition air strikes that targeted jihadists.
Jordan had been attempting to secure Lt Kasasbeh’s release as part of a prisoner swap, offering to free Iraqi militant Sajida al-Rishawi in return for the release of Lt Kasasbeh.
As reported by BBC News.
The video is 22 minutes long…ugh, i know, so if you don’t want to watch the whole thing then you can skip to about the 17 minute mark when they begin the burning.