The father of an American college student released by North Korea and now in a coma in hospital has said his son was "terrorised and brutalised" by his captors.
Speaking from his Ohio home, Fred Warmbier told Fox News' Tucker Carlson that his son Otto "is not in great shape right now".
University of Virginia student Otto, 22, landed in Cincinnati late on Tuesday and was taken by ambulance to hospital.
His parents say he has been in the coma for more than a year.
Mr Warmbier senior says he does not know exactly what happened to his son during his 17-month detention.
Otto Warmbier was serving a 15-year prison term with hard labour after he tearfully confessed that he tried to steal a propaganda banner while visiting North Korea.
Mr Warmbier's full interview will be shown on Fox News on Thursday night.
Former New Mexico governor Bill Richardson said there should be an investigation into what happened to Mr Warmbier, saying it was a "tragic situation".
The Democrat and former US ambassador to the United Nations praised the Department of State for working to bring Mr Warmbier home.
But he said the US government had to respond forcefully if it was determined Mr Warmbier's condition was not disclosed "and he didn't get proper treatment".