American aide worker Peter Kassig beheaded by ISIS

American aid worker and former soldier Peter Kassig was beheaded by ISIS terrorists, the White House confirmed Sunday, hours after a video claiming to show the victim surfaced online. ISIS held Kassig as a hostage and in previous communications had threatened his life.

The video shows the aftermath of a beheading in which the victim is not clearly recognizable. President Barack Obama confirmed the 26-year-old's beheading, saying

Kassig was taken from us in an act of pure evil by a terrorist group that the world rightly associates with inhumanity."

 Kassig, who converted to Islam in captivity, also went by the name Abdul-Rahman Kassig.

He first traveled to the Middle East as a U.S. soldier and returned as a medical worker, feeling compelled to help victims of war. He did aid work in Syria, where he was captured. He was held hostage for over a year.

"We are heartbroken to learn that our son, Abdul-Rahman Peter Kassig, has lost his life as a result of his love for the Syrian people and his desire to ease their suffering," Kassig's parents, Ed and Paula, said in a statement.

The parents released a previously unpublished audio recording of their son, recorded by a journalist before Kassig was taken captive.

You know we would have a chance here to make up for a lot wrong that we did in this part of the world if we stepped in, in the right way, Peter Kassig says in the recording. If we just as a country did what other people helped me to do in that hospital. How much did I impact the political situation inside Syria? None. How much did I impact the political situation back home? None. But what I did do is that over period of time in that hospital I was able to share a little bit of hope and comfort with some people.

The Kassig family expressed heartbreak over the beheadings of the other Westerners who came before their son, and asked for prayers for the safe return of other captives.

While ISIL revels in the slaughter of innocents, including Muslims, and is bent only on sowing death and destruction, Abdul-Rahman was a humanitarian who worked to save the lives of Syrians injured and dispossessed by the Syrian conflict,Obama said.

ISIL is another term for the group ISIS, the Islamic State in Iraq and Syria, which calls itself simply the Islamic State.