The family of student Otto Warmbier, who was held prisoner by North Korea for a year and a half before he was returned to his family in a vegetative state and died soon afterward, filed a wrongful death lawsuit against the North Korean government on Thursday.

“Otto was taken hostage, kept as a prisoner for political purposes, used as a pawn and singled out for exceptionally harsh and brutal treatment by Kim Jong Un,” said Otto’s father Fred Warmbier. “Kim and his regime have portrayed themselves as innocent, while they intentionally destroyed our son’s life. This lawsuit is another step in holding North Korea accountable for its barbaric treatment of Otto and our family.”

The complaint alleges that North Korea has “repeatedly lied about the causes of Otto’s condition and refuses to acknowledge its abhorrent actions.”

“In fact, North Korea, which is a rogue regime, took Otto hostage for its own wrongful ends and brutally tortured and murdered him,” the suit charges.

The lawsuit describes Fred and Cindy Warmbier as “stunned to see his condition” when North Korea returned their son, saying, “He had a shaved head, a feeding tube coming out of his nose, was jerking violently and howling, and was completely unresponsive to any of their efforts to comfort him.”

The suit also charges North Korea with extracting a forced confession from Otto, who was compelled to admit to subversive activities on North Korean state television. It asks for both “economic and non-economic compensatory damages” for his “extrajudicial killing.”

The North Korean government has denied responsibility for Otto Warmbier’s death, claiming sleeping pills and a case of botulism put him in a coma. No sign of botulism was found when he was examined by doctors and a coroner in the United States. The precise cause of his death could not be determined; the coroner attributed it to an “unknown insult more than a year prior to his death” and complications from the resulting brain injury.

The New York Times reviews the legal environment facing the Warmbiers, concluding that the suit has a chance of moving forward but it is highly unlikely the North Koreans will pay whatever damages might be awarded:

Under American law, private citizens are not eligible to sue foreign countries. But Mr. Trump placed North Korea on the State Department’s list of state sponsors of terrorism in November—restoring it to a list it had been on from 1988 to 2008. That opened it to lawsuits from victims of terrorism. If the Warmbiers are awarded compensatory damages, they can draw from the United States Victims of State Sponsored Terrorism Fund, established by Congress to pay out claims, with a cap of $20 million per person, or $35 million for a group of plaintiffs.

The White House expressed support for the Warmbier lawsuit despite the delicate negotiations currently in progress with North Korea. In fact, one senior administration official told the NYT the suit could be useful for pressuring Pyongyang to release the three Korean-Americans it still holds prisoner. President Trump has promised to push for their freedom when and if he meets with North Korean dictator Kim Jong-un.

“Although this is a private legal action to which the United States government is not a party, Americans remain committed to honoring Otto’s memory, and we will not forget the suffering of his parents, Fred and Cindy Warmbier,” White House Press Secretary Sarah Huckabee Sanders said on Thursday.