Peter Kassig’s family has been attempting to reach ISIL, the Islamic extremist group holding their son hostage, in an attempt to convince the group to release Kassig. The family has used social media to reach the group but there has been no response.

In a Tweet sent out on Wednesday, Paula Kassig asks ISIL’s leader Abu Bakr Al Baghdadi to release her son. During his captivity, Peter voluntarily converted to Islam and adopted the Arabic name Abdul Rahman.

Despite saying, “We would like to talk to you. How can we reach you?” and retweeting the message multiple times and translating it into Arabic, the family has received no response.

Kassig, a former U.S. soldier who started a non-profit to help the Syrian people in the country’s civil war, was kidnapped by ISIL last year. He appeared at the end of an ISIL video that showed the execution of British humanitarian worker Alan Henning.

Kassig’s family has been desperately trying to reach the extremist group in an attempt to free their son. According to Newsweek, the family released on Sunday via Twitter a statement as well as part of letter he sent them in June.

“I am obviously pretty scared to die but the hardest part in not knowing, wondering, hoping, and wondering if I should even hope at all,” he writes. “I am very sad that all this has happened and for what all of you back home are going through. If I do die, I figure that at least you and I can seek refuge and comfort in knowing that I went out as a result of trying to alleviate suffering and helping those in need.”

He also thanks his parents for giving him strength and a good upbringing and tells them he loves them. His parents released part of the letter so others may understand their experience better.

“We have decided to release portions of his June 2014 letter, so the world can understand why we and so many people care for him and admire him,” the statement said. “We ask the world to continue to pray for him and for all innocent people harmed by violence and war.”

The family also released a video on YouTube addressing the ISIL leadership.