'Terrorists': Otto Wambier's parents speak out on son's death after North Korea prison camp

The parents of a young US man who was detained in North Korea for more than a year and died soon after being released said he was howling, "jerking violently" and "staring blankly" when he returned home on a medical flight.

Fred and Cindy Warmbier appeared on Fox News amid an escalating war of words between the Trump administration and North Korea, claiming the rogue state’s people are "terrorists".

It comes after a North Korean official has claimed President Donald Trump has, in effect, declared war, which the White House denied.

Otto Warmbier died on Monday at 2.20pm surrounded by family

Otto arrived in the US in a serious medical condition and had to be carried off the plane. Source: Reuters

Otto Warmbier's father said they wanted to speak out about their son’s condition after hearing North Korea claiming to be a victim that's being picked on.

• Illness or torture? What killed the American student detained by North Korea?

• Girlfriend pays tribute to 'soulmate' US student who died after North Korea detention

• Revealed: Life inside North Korea's torturous prison camps

"North Korea is not a victim. They're terrorists," Mr Warmbier said.

"They kidnapped Otto. They tortured him. They intentionally injured him. They are not victims."

Otto's parents called North Koreans "terrorists". Source: Fox News

North Korean officials said Warmbier fell into a coma after his trial. Photo: AAP

Otto was sentenced to 15 years of hard labour in March 2016 for allegedly stealing a propaganda poster.

His parents described the horrifying condition his family found him in when they went aboard an air ambulance that arrived on June 13 in Cincinnati.

They said Otto, a 22-year-old University of Virginia student, was howling, making an "involuntary, inhuman sound" and was blind and deaf with his head shaved.

Otto was sentenced to 15 years hard labour but returned home to the US after serving only one year. Source: AP

Otto's parents say their son returned home in agony. Source: AP

The parents described their son as "staring blankly into space jerking violently".

Fred Warmbier said his son’s mouth "looked like someone had taken a pair of pliers and rearranged his bottom teeth".

He said Otto's mother and sister ran off the plane at the initial sight of him.

Warmbier's father Fred lashed out at Kim Jong-Un's authoritarian state last week. Photo: Getty

“What we pictured, because we’re optimists, was that Otto would be asleep and then maybe in a medically-induced coma. And when our doctors here would work with him and he would get the best care and love that he would come out of it,” his mother Cindy said.

"We weren't prepared ... no mother, no parent should ever have gone through what we went through," Mrs Warmbier said.

She said it was "inexcusable" that her son had been alone in captivity for so long with no one to comfort him.

• Tillerson Delivers Statement on Release of Otto Warmbier From North Korea

• CCTV shows US student stealing propaganda North Korean banner from hotel wall

She said she "got it together" and stayed with him after his arrival.

“Within two days of Otto being home, his fever spiked to 104 degrees. He had a large scar on his right foot. North Korea is not a victim ... they purposefully and intentionally injured Otto," she said.

President Trump tweeted about the family's appearance, calling it "a great interview".

Warmbier's parents declined an autopsy. Photo: Getty

He accused North Korea of brutally abusing an American student who had been held captive in North Korea, saying the young man had been "tortured beyond belief".

Trump had previously blamed Pyongyang's "brutal regime" for Warmbier's plight but it was the first time the president publicly accused North Korea of torture in the case.

US officials have said Trump was personally taken aback by Warmbier's death and his comment Tuesday ratchets up the pressure on Kim Jong-Un's regime.

Mr Warmbier also said Otto had a large scar on his right foot and a high fever.

He had previously criticized former president Barack Obama's administration for how little it did for their son, saying officials had counselled the family against speaking out to avoid antagonizing the North Korean regime.

Otto died less than a week after returning at University of Cincinnati Medical Centre.

PICTURED: Otto Warmbier with his girlfriend at the time of his detention, Alex Vagonis. Source: Facebook

North Korea has denied mistreating the youth.

The Warmbiers now want North Korea listed as a state sponsor of terrorism.

Three Americans accused of various crimes against the state are behind bars in the North, which is engaged in a tense standoff with the Trump administration over its banned missile and nuclear weapons programs.