But the Warmbier family heatedly disputed that claim, saying North Korea had "brutalized" Otto.
McCain, the Republican chairman of the Armed Services Committee, condemned the treatment of the 22-year-old University of Virginia student, who he said was "murdered by the Kim Jong-un regime". "The United States of America can not and should not tolerate the murder of its citizens by hostile powers".
The regime said that it had released him "on humanitarian grounds".
Fred Warmbier praised his son's "performance" and President Donald Trump's administration. He's also a rare Western detainee who came out of the country in rough shape _ the vast majority of Americans detained by the North have been released in relatively good condition.
He had been sentenced to 15 years of hard labor after being arrested during a trip with Young Pioneer Tours, a China-based tour company. He was arrested while headed back to China, for allegedly removing a propaganda poster.
Warmbier was medically evacuated from North Korea on June 13 following diplomatic talks at the top of the USA government. He was leaving North Korea on January 2, 2016, when he was detained at the airport. Americans would be barred from visiting as tourists.More news: Lookers PLC (LOOK) Receives GBX 170 Average Target Price from Analysts
More news: Creamfields to Show McGregor vs. Mayweather Fight
More news: Revenue Estimates Analysis Cliffs Natural Resources Inc. (CLF)
"The United States once again condemns the brutality of the North Korean regime as we mourn its latest victim". "Worse, the regime has routinely imprisoned innocent foreign civilians and used them as bargaining chips to gain credibility with the West". Trump said in April that the USA was preparing for a "major conflict" with the reclusive state.
Secretary of State Rex Tillerson told a House committee last week that the administration may implement such a ban. "Working with such a country, we must achieve the goal of the complete dismantlement of North Korea's nuclear program", he said.
Young Pioneer Tours adventure travel company, based in China, reconsidered its position on taking USA citizens on tours to North Korea and will no longer organize their trips to the country, according to the agency's statement published on Tuesday. However, he did not mention a travel ban.
It jars so strikingly with the fates of most past detained Americans that outside observers are left struggling not only with the mystery of what killed Warmbier but also with what his death means for attempts by Washington and its allies to stop North Korea's pursuit of a nuclear-tipped ICBM that can target the US mainland.
Moon, who was elected on a plan to engage in talks with North Korea, said he agreed with Trump on being willing to participate in a dialogue with North Korea under certain conditions, given that sanctions and worldwide pressure have not resolved the situation. North Korea accuses the United States and South Korea of sending spies to overthrow its government.
Warmbier, a student at the University of Virginia, was on a tour of North Korea early a year ago when he allegedly tried to steal a propaganda banner from his hotel and was charged with hostile acts against the state.