Earlier reports of Warmbier's condition stated North Korean officials claimed he had contracted botulism, and he fell into a coma after he was given a sleeping pill.
To honor his son, Fred Warmbier wore the same jacket Otto wore when North Korea presented him before the media on February 29, 2016, at an event where he tearfully confessed that he tried to steal a propaganda banner while visiting the country.
Fred Warmbier, father of Otto Warmbier, speaks during a news conference, June 15, 2017, in Cincinnati. "There's no excuse for the way North Koreans treated our son".
It's unclear if Yun knew as he set off for North Korea that he'd be allowed to bring Warmbier home.
A White House spokeswoman says Warmbier's release "was a big priority" for President Donald Trump.
On Thursday, North Korea said that it had released Warmbier "on humanitarian grounds".
"We relied on this false premise that they would treat Otto fairly and let him go", Warmbier said. He says the administration is heartened Warmbier has been reunited with his family. He said the president was "very candid" during the telephone call and told him Secretary of State Rex Tillerson and other USA officials worked hard to negotiate Otto's release.
He arrived on a military airplane in his home town late on Tuesday.
U.S. Secretary of State Rex Tillerson told reporters on Thursday, "We're glad he's home". He said an MRI from North Korean doctors dated April previous year showed damage that would be consistent with Warmbier's current condition.
"Tests did not reveal any evidence of active or chronic denervation or any repetitive stimulation that would suggest active botulism at this time", Dr. Brandon Foreman said at a press conference.
North Korea released U.S. student Otto Warmbier "on humanitarian grounds", state media said yesterday, two days after he was evacuated from Pyongyang after falling into a coma while imprisoned in a labour camp.
It took months of "quiet diplomacy", a change in US presidents and an American diplomat's extraordinary, secret visit to Pyongyang to bring Otto Warmbier home.
A brain scan showed extensive loss of tissue in all regions of the brain, but doctors said there was no "certain or verifiable knowledge of the cause or circumstances of his neurological injury".
They said his prognosis remains confidential.
In a separate statement, Otto Warmbier's doctors described his condition.
"Otto is a fighter", he said.
White says she kept in touch with the University of Virginia student after he left her class. "But I did take the call, and it was gracious, and it was nice, and I thank him for that".
Warmbier was imprisoned in North Korea for 17 months.
He arrived in Cincinnati earlier this week in a comatose state.
His condition is stable, but he has experienced a "severe neurological injury". Doctors planned an update later Thursday.
He said he felt "anger that [Otto] was so brutally treated for so long" but was relieved his son was "now home in the arms of those who love him".
Doctors treating an American college student who was released by North Korea in a coma plan to discuss his medical condition. The doctors said Thursday that there were no clear signs of physical trauma, such as scars or bone fractures.
His father, Fred Warmbier, said the family was proud of their son, calling him "a fighter".
He said Otto "is not in great shape right now" and that his family is "adjusting to a different reality".
US special envoy Joseph Yun was a household name to nearly no one before Warmbier's return to OH on Tuesday, yet he joins an exceedingly short list of USA officials to set foot in furtive North Korea in recent years.
Warmbier says he worked behind the scenes with USA and Swedish officials to get his son out. He said he and his wife, Cindy, only learned of their son's condition last week. He was then taken by ambulance to a hospital.