Mr Warmbier "shows no understanding of language" and has "extensive loss of brain tissue", which was likely caused by cardiopulmonary arrest, he said.
A University of Cincinatti hospital representative says UVa student Otto Warmbier suffered a "severe neurological injury" during his captivity, and his father said they are just trying to keep him comfortable at this point.
The North's KCNA news agency said in a dispatch that the decision to release the 22-year-old American student followed a court decision.
His father, Fred Warmbier, wearing the same jacket his son wore to a North Korean courtroom, told reporters his family does not believe the North Korean regime's account of how his son fell into a coma shortly after being sentenced at a show trial in March 2016.
Fred Warmbier said he was stunned when told of his son's condition one week ago.
Warmbier is now at the University of Cincinnati Medical Center and is in a #Stable Condition.
Warmbier's father, Fred Warmbier, expressed skepticism about the North Korean government's reason for his son's illness.
Most people will make a full recovery with treatment, but the paralysis can spread to the muscles that control breathing if it's not treated quickly.
Doctors said they also examined the rest of Warmbier's body and saw no evidence of fractures in his skull or elsewhere that might be evidence of severe beatings.
"The North Koreans lure Americans to travel to North Korea via tour groups that are run out of China who advertise slick ads on the internet proclaiming that "No American ever gets detained off our tours" and 'This is a safe place to go, '" Warmbier said. He said they made multiple trips from their suburban Cincinatti home to Washington over the time of Otto's captivity. On June 6 in New York, Yun met with North Korean diplomats and was informed about Otto's condition for the first time.
A medical team from the University of Cincinnati Medical Center described Otto Warmbier's condition as a "state of unresponsive wakefulness". "We are extremely grateful for their efforts and concern", he said. Blue-and-white ribbons were tied around trees and utility poles along the main road.
Asked whether he thought the previous administration could have done more, Warmbier replied: "I think the results speak for themselves". "But I did take the call, and it was gracious and it was nice and it felt good, and I thank him for that". "Fred, Cindy and the Warmbier family have been remarkably strong throughout this ordeal".
Warmbier said Trump was "very candid" during the call and told him Secretary of State Rex Tillerson and other USA officials worked hard to negotiate Otto Warmbier's release.
Warmbier's release came after a flurry of secret diplomatic contacts between Washington and Pyongyang, which culminated in Joseph Yun, the State Department's special envoy on North Korea, travelling to Pyongyang to secure Warmbier's release. "I'm so proud of Otto, my son, who has been in a pariah regime for the last 18 months - brutalized and terrorized".