The Islamic State released a video on Tuesday that purports to show a Jordanian pilot, Lt. Muath al-Kaseasbeh, being burned alive by his captors.

According to the SITE monitoring group, which follows militant Web sites, the 22-minute video, titled “Healing of the Believers’ Chests,” was released on social media even as Jordan struggled to learn his fate.

Shortly after the video appeared online, Jordanian state TV reported that the pilot was killed on Jan. 3. It gave no further details on how the date was determined, but it suggested that it was new information because Jordanian officials sought “proof of life” evidence from the Islamic State as recently as earlier this week.

The killing appears to mark an effort by the Islamic State to present increasingly gruesome acts. Previously, the group decapitated its captives and then showed the head sitting on top of the body. Execution by decapitation in the Arab world, especially in Saudi Arabia, a U.S. ally, is not uncommon.

Burning the pilot to death would represent a stunning escalation.

President Obama, speaking to reporters in Washington, said he was not yet briefed on the details of the video, but he called it “just one more indication of the viciousness and barbarity” of the Islamic State.

Hours earlier, before the release of the video, Secretary of State John F. Kerry met with Jordan’s King Abdullah II and the country’s foreign minister, Nasser Judeh, as part of a visit to sign a deal for further U.S. aid to Jordan. The Jordanian officials in Washington had no immediate comment on the video.

National Security Council spokeswoman Bernadette Meehan said in an e-mail that the U.S. government was aware of the video and that “the intelligence community is 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. We stand in solidarity with the government of Jordan and the Jordanian people,” she added.

The Islamic State, an al-Qaeda offshoot also known as ISIS or ISIL, released a video over the weekend that appeared to show the beheading of Kenji Goto, a Japanese journalist.

The video did not mention Kaseasbeh’s fate. However, the Islamic State had previously said it would kill both Kaseasbeh and Goto if Jordan failed to meet a Thursday deadline to release an Iraqi woman convicted of a role in 2005 bombings that killed 60 people in Jordan’s capital, Amman.

The pilot was captured by the Islamic State in December, after his plane crashed in Syria during a bombing run. Although the Islamic State claimed that it had shot down his plane, U.S. Navy Cmdr. Lisa Brackenbury, a Central Command spokeswoman, said in December that while “a thorough investigation will be conducted, this was an aircraft crash and not the result of enemy action.”

Late last year, the Islamic State posted social media images of Kaseasbeh, 26, surrounded by masked militants, as his captors pulled him from a body of water.

According to SITE, the video shows “media footage of Jordan’s involvement in the U.S.-led coalition” against the Islamic State. Then, the video shows Kaseasbeh, with a black eye, “discussing Jordan’s operation in a news-style monologue.” The video then juxtaposes images of the pilot surrounded by militants, and images of the aftermath of bombings.

“At the end of the video, [Kaseasbeh] stands inside of a cage and is burned alive by fighters,” SITE writes.

Reuters  reported that the head of Jordan’s armed forces personally notified Kaseasbeh’s family of the pilot’s death.

The killing risks undermining a U.S.-led coalition fighting the Islamic State, which has seized large swaths of territory in Iraq and Syria.

Jordan has absorbed a flood of refugees fleeing the militants from the civil war in Syria and the uprisings in Iraq. Jordan’s air force and intelligence agencies are active, public partners in the U.S. coalition against the Islamic State.

The capture of the Jordanian pilot, however, sparked an antiwar movement calling for Amman to pull out of the coalition. Kaseasbeh is from a large and influential tribe centered in Karak, a province south of Amman, and his people have been staging protests in front of government buildings. The demonstrators have stressed not only the pilot’s capture, but the growing number of Syrian civilians caught in the bombings.

The Jordanian government said last week it was prepared to swap a prisoner sentenced to death for her role in the 2005 Amman hotel bombings for the Jordanian pilot.

Jordan’s sensational offer to free the suicide bomber, an Iraqi whose device failed to explode, illustrated the tremendous pressure that Jordan’s King Abdullah II and his government have faced over the pilot’s capture.

Last week, Jordanian Foreign Minister Judeh said his government insisted that the Islamic State offer “proof of life” that the pilot was alive before they released the Iraqi woman, who is serving a sentence on death row.

Judeh tweeted last week, “Unfortunately we have heard nothing.”

As the deal appeared to fall apart last week, the Islamic State released an audio recording during the stalled negotiations threatening to kill the pilot.

The Jordan pilot’s release was being sought at the same time that diplomats and families pleaded for the lives of two Japanese hostages, a journalist and an adventurer, both of whom were subsequently beheaded by the Islamic State.

[This post has been updated multiple times.]