Otto Warmbier’s parents are demanding $1.1 billion from North Korea in compensation for their son’s d‌e‌at‌h.

Warmbier was a‌rr‌est‌e‌d for allegedly ste‌al‌in‌g a propaganda poster in January 2016. Originally se‌n‌te‌nc‌e‌d to 15 years of hard labor, he returned to the U.S. in a co‌m‌a and ‌d‌‌i‌e‌‌‌d later in June 2017.

Fred and Cindy Warmbier are seeking the amount based on the similar case of Kim Dong-shik, a Korean-American pastor who d‌ie‌d‌ in 2015.

According to the Korea Times, a sum of $1.05 billion — the largest portion — will be for punitive damages, while $350 million will be reserved for each parent.

Additionally, the Warmbiers are demanding $10 million for the psychological pain Otto had gone through during his detention. They also want $15 million more for each of them for the psychological p‌a‌in they had to endure whenever their son appeared on North Korean TV and when they decided to halt his life support.

Financial losses were also taken into account.

“Physically, he returned de‌str‌oye‌d in a state of unresponsive wakefulness with a devastating brain i‌nj‌u‌ry; he also had a large scar on his left foot and traumatic dental inj‌‌u‌ries, all of which resulted from North Korea’s t‌ort‌ur‌e,” the lawsuit filed in April stated, according to Voice of America.

North Korea has not responded to the lawsuit yet. As such, no representative was present for the pre-trial hearing on Dec. 14.

According to the Chosun Ilbo, the Warmbiers’ lawyers said that if the $300 million awarded in Kim’s case was not enough to stop North Korea, “more must be awarded here to send a message to North Korea that its continuing heinous acts will be met with ever increasing penalties.”

The Warmbiers recently visited Japan to speak at a symposium that discussed North Korean abduction cases, the Korea JoongAng Daily reported. The event was sponsored by the Japanese government.

“As a victim of North Korean terror, I feel a kinship especially with the loved ones of the abductees,” said Fred, adding that he was visiting Tokyo so as “not to forget the d‌e‌a‌th‌ of my son.”