The pilot, Lt. Muath al-Kasasbeh, is shown in an orange jumpsuit in an outdoor cell before he is set on fire.
The undated video of al-Kasasbeh’s apparent death comes just days after ISIS uploaded another video showing what appeared to be the decapitated head of a Japanese hostage, journalist Kenji Goto.
Last week the Jordanian government had offered to release an al Qaeda prisoner in exchange for al-Kasasbeh, but officials said ISIS failed to prove that the pilot was alive. In addition, while ISIS said then they would release Goto for the al Qaeda prisoner, they did not offer al-Kasasbeh’s freedom.
Amid conflicting information, U.S. intelligence did not know if the pilot was alive as of the weekend, a defense official told ABC News. Some intelligence pointed to al-Kasasbeh having been killed weeks before. He was not shown in the public communications between ISIS and the Jordanian government.
Jordanian officials believe al-Kasasbeh was killed back in Jan. 3, according to a statement from the Jordanian armed forces posted on Jordanian state television’s website. The statement did not explain how the military came to that conclusion.
Prior to his death in the video, al-Kasasbeh speaks to the camera, explaining that he was captured by ISIS after his plane was hit during an anti-ISIS operation in December.
“My aircraft took a hit, [another officer] let me know there was fire coming out of my plane. I checked my signals and realized my engine was no longer functioning. I ejected myself. I fell into the river and was taken prisoner by the ISIS fighters,” he says.
In the last months ISIS has released a string of disturbing videos in which hostages, including several Western civilians, are decapitated, but death by fire appears to be a new tactic.
King Abdullah of Jordan said that the "courageous pilot died defending his faith, his country" and called for Jordanians to "show the mettle of the Jordanian people in facing the challenges that will only make us stronger and more united."
A spokesperson for the White House National Security Council said the U.S. intelligence community is aware of the video and is "working to confirm its authenticity."
"The United States strongly condemns [ISIS's] actions and we call for the immediate release of all those held captive by [ISIS]," spokesperson Bernadette Meehan said. "We stand in solidarity with the Government of Jordan and the Jordanian people."
ISIS is believed to be holding a number of hostages, including a 26-year-old American woman.
Sen. John McCain (R-Ariz.) told ABC News the video was “just another manifestation of the evil that we’re facing and the administration has done nothing.”
“They are not losing. ISIS is not losing. I promise you,” he said.
President Obama told reporters shortly after the video's release that it will only make the coalition "redouble" its efforts against the terror group.
"I think we’ll redouble the vigilance and determination on the part of our global coalition to make sure they’re degraded and ultimately defeated," he said. "It also just indicates the degree to which whatever ideology they’re operating off of, it’s bankrupt."
ABC News' James Gordon Meek and Arlette Saenz contributed to this report.