The family of the Arizona woman who Islamic militants claim was killed in a Jordanian airstrike is hoping she is still alive.

Kayla Jean Mueller's parents are not speaking to reporters, but issued a statement through a family representative late Friday asking for privacy and requesting that the so-called Islamic State, which has held the aid worker since 2013, contact them privately.

Jordan called ISIS's claim "criminal propaganda," and U.S. officials say they can't confirm her death, says Martin Kaste of our Newcast desk.

"ISIS is claiming she was killed in this Jordanian airstrike, but that's a very convenient thing for ISIS to say right now, and it's not known for sure how she died, or whether she died," Kaste reports.

Jordan launched strikes against ISIS after the extremists released a video this week showing a Jordanian hostage, pilot Lt. Muath al-Kaseasbeh, being burned to death.

Carl and Marsha Mueller's statement addressed "those in positions of responsibility for holding" their daughter.

"This news leaves us concerned, yet, we are still hopeful that Kayla is alive. We have sent you a private message and ask that you respond to us privately. We know that you have read our previous communications, [kidnapped British journalist] John Cantlie made references to them in October."You told us that you treated Kayla as your guest, as your guest her safety and wellbeing remains your responsibility."Kayla's mother and I have been doing everything we can to get her released safely."

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