Doctors Without Borders has released a statement in its defense, noting Mueller wasn't an employee of the group and wouldn't have been let into Syria if she had been. The Prescott, Arizona, native was originally taken by the terrorist organization while doing humanitarian work in Aleppo, Syria, with a Doctors Without Boarders contractor.

In the 10-second clip from 2013, Kayla Mueller, 26, is seen clad in a green hijab with a black scarf wrapped around her head speaking directly to the camera. She had been missing from the war-torn city of Aleppo for nearly a month by the time this ISIS-made video was received by a friend of Meuller's, who gave it to the Federal Bureau of Investigation.

Her mother, Marsha, said her daughter looked thin in the video, but her eyes were "clear and steady". "I need your help", she was reported as saying in the video. "I've been here too long and I've been very sick and it's very terrifying here".

In the video, which was taken about a month after her capture, Mueller doesn't say much. "They want us to see that overall she's not in bad shape", Voss told ABC News.

"You just go into nearly a catatonic state", her dad said, describing his reaction to first seeing the footage.

Chris Voss, a retired Federal Bureau of Investigation hostage negotiator who secured USA citizen's release from Iraq, told ABCNews, "They could've said, 'Yes, you work for us.' And they could've extended her some sort of protection, some sort of legitimacy that would've cost them nothing".

"But I also saw her strength". "They produce these the same way any media company produces videos". "This is, 'We want to talk, '" Voss told ABC News. They rehearsed her. They got the lighting right. He said MSF were not hostage negotiators and it would have put their own staff and work at risk.

Their faith in aid groups and the government meant that the Muellers did not begin negotiations with the hostage takers for 10 months, when Doctors Without Borders turned over an ISIS email address, two months after the aid group received it from some of its workers freed from captivity.

Negotiations started 10 months after her capture on 23 May 2014 once MSF (known in the USA as Doctors Without Borders) handed over an Isis email address, two months after they had received it from some of their workers who had been freed from captivity. "If we start engaging in negotiating for the release of non-staff members, we increase the risk to our teams that are already taking grave risks to provide medical care in the [sic] some of these places that Kayla wanted to provide help to", the Doctors Without Borders executive explained.

"Mom and Dad, I still am remaining healthy", she said in the recording, according to ABC. Cone elaborated "We can't be in the position of negotiating for people who don't work for us". ISIS had Kaya record an audio clip, demanding the release of Dr. Afia Siddiqui in exchange for her freedom. "If this is not achievable, they are demanding 5 million euros to ensure my release", Kayla said.

In a last words to her parents, she said: "Goodbye".