Transcript for Otto Warmbier dies days after returning to U.S.

Good evening. And it's great to have you with us here on a Monday night. And we begin with late developments today. The worsening horror for a mother and father from Ohio. Their son, who was returned from North Korea was severe brain damage, has now died. This was the moment Otto Warmbier was returned, after more than a year in captivity. His parents reacting just a short time ago, pointing to the quote awful mistreatment at the hands of the north Koreans that did this. ABC's chief global affairs correspondent Martha Raddatz leading us off tonight. Reporter: He arrived in the U.S. Less than a week ago. Carried off a plane, suffering from extensive brain damage, more than a year since the world heard his plea for mercy. Please, save my life. Please think of my family. Reporter: In a statement today, his parents say when Otto was carried off that airplane, he looked very uncomfortable, almost anguished. But within a day, the count innocence of his face changed. He was at peace. He was home, and we believe he could sense that. But he could not walk, talk or respond to verbal commands. And today, he passed away, surrounded by his family. Since the moment their son was sentenced to hard labor for stealing a propaganda poster, the warm beiers were fighting until he was released. We're thrilled that our son is on American soil and I'm able to talk to you on Otto's behalf and I'm able to wear the jacket that he wore when he gave his confession. Reporter: The family clearly blames North Korea for Otto's death, saying today the awful, torturous mistreatment or son received at the hands of the north Koreans ensured that no other outcome was possible. And Martha Raddatz joins us live tonight. We still don't know what caused that brain damage, and just moments ago, president trump responding to news of his death? Reporter: David, he made some brief comments before the beginning of a meeting, saying that a lot of bad things happened to Otto while in north Korea, but at least they were able to get him home to be with his parents. The white house also said it deepens the administration's determination to prevent such tragedies but there was no indication that there will be any response beyond that statement, David, to Otto's death. Martha Raddatz leading us off tonight. Martha, thank you.

This transcript has been automatically generated and may not be 100% accurate.