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LONDON — ISIS militants released a video Tuesday purporting to show a captive Jordanian pilot being burned alive in a cage, just days after the militants beheaded a Japanese journalist.

Lt. Muath al Kasasbeh was on a bombing run over Syria in December when he was forced to eject and was immediately captured by ISIS fighters. His continued captivity — and ISIS threats to murder him — have been a national trauma for Jordan.

A 22-minute video released by the al-Furqan Media Foundation — one of the official media arms of ISIS — shows Kasasbeh with a black eye at a table and, later, standing in a cage as he is burned alive. The tape appears consistent with other ISIS videos, according to Flashpoint Intelligence, a global security firm and NBC News consultant.

The spokesman for Jordan's armed forces, Mamdouh al-Ameri, confirmed Kasasbeh's death. In a televised statement, he vowed "revenge" for the "hero pilot," according to The Associated Press and Reuters.

King Abdullah, who was already in Washington, was scheduled to meet with President Barack Obama early Tuesday evening and then fly home early.

Abdullah called Kasasbeh a "brave martyr," saying in a statement: "Such a horrific crime has no link to our religion, in any way. Muath, the brave pilot, endured in defense of his tribe, his nation, and his country, and has followed the likes of the martyrs that preceded him, who gave their lives and their blood for our dear Jordan."

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While the video bears some similarities to previous hostage videos, it also bears some notable differences. Like previous murdered hostages, Kasasbeh is pictured in an orange jumpsuit. But instead of black-clad fighters wielding knives, he is surrounded by militants in sand-colored balaclavas and camouflage.

One militant lights a torch and a trail leading toward a cage holding Kasasbeh. The pilot raises his hands to his head and screams as he is engulfed by flames. A tractor then dumps rocks and sand onto the cage to extinguish the blaze.

Kasasbeh was the first pilot from the U.S.-led coalition against ISIS to be captured — which most likely explains the grisly change in tactics, said Laith Alkhouri of Flashpoint.

"For ISIS, this is 'equal' to the bombing and burning of purported civilians and children by the aerial bombardment," he said. "The group is essentially saying 'an eye for an eye.'"

The White House is aware of the video and the intelligence community is working to verify its authenticity, said Bernadette Meehan, a spokeswoman for the National Security Council .

"We stand in solidarity with the government of Jordan and the Jordanian people," she added.

Obama told reporters at a White House event on the Affordable Care Act that he had "just got word" about the video.

"Should, in fact, this video be authentic, it's just one more indication of the viciousness and barbarity of this organization," he said in response to a question shouted at the end of the event.

Jordanian officials had been working feverishly to negotiate a prisoner swap in exchange for the pilot following the murders of the journalist and another Japanese citizen last month. On Sunday — a day after ISIS beheaded journalist Kenji Goto — Jordan renewed an offer to swap an al-Qaeda prisoner for Kasasbeh.

The fate of the pilot and Goto were first linked when ISIS demanded the release of Sajida al-Rishawi, an al-Qaeda prisoner who faces death by hanging for her role in triple hotel bombings in Jordan in 2005. An audio message last week, purportedly from ISIS, said only that the pilot would be killed if al-Rishawi was not released Thursday. Al-Rishawi remains in Jordan.

Andrea Mitchell and Erin McClam of NBC News, The Associated Press and Reuters contributed to this report.