The parents of Otto Warmbier say North Korean leader Kim Jong Un is responsible for their son's death, a rebuke to statements made earlier in the week by President Donald Trump.

"Kim and his evil regime are responsible for unimaginable cruelty and inhumanity," Fred and Cindy Warmbier said in a statement released Friday morning. "No excuses or lavish praise can change that."

Trump said Thursday he did not hold Kim responsible for the death of Warmbier, the Wyoming, Ohio, college student who died after being imprisoned in North Korea.

Politicians and diplomats across the spectrum had expressed disbelief Thursday at Trump’s assertion that North Korean leader Kim did not know what happened to Otto Warmbier while the suburban Cincinnati man was in custody in Pyongyang.

The president made the observation about Kim at Thursday's close of his summit in Hanoi, Vietnam, with the North Korean leader. The meeting ended early without an agreement on the key goal, regulating that nation’s nuclear program.

At the concluding news conference, Trump was asked about Warmbier, and the president said he does not hold Kim responsible, saying, "I don't believe he knew about it. He tells me that he didn't know about it and I will take him at his word."

Friday afternoon Trump said in a series of tweets he was being "misinterpreted."

"I never like being misinterpreted, but especially when it comes to Otto Warmbier and his great family. I got Otto out, along with three others. The previous Administration did nothing and he was taken on their watch. Of course I hold North Korea responsible for Otto’s mistreatment and death. Most important, Otto Warmbier will not have died in vain. Otto and his family have become a tremendous symbol of strong passion and strength, which will last for many years into the future. I love Otto and think of him often!"

Trump's tweet did not address the source of controversy - whether Kim himself was responsible for Warmbier's death.

More:Trump believes Kim Jong Un didn't know about Otto Warmbier. Experts say that's impossible.

More:President Trump on Otto Warmbier: From 'brutal regime...we'll handle it' to 'I will take (Kim) at his word.'

How Warmbier died

Warmbier, a student at the University of Virginia, went to North Korea on a tourist vacation in late 2015 and was about to return in the first days of 2016 when he arrested and charged with stealing a poster from a Pyongyang hotel. After a show trial, a North Korean court sentenced Warmbier to 15 years hard labor.

Immediately after the sentencing, however, no further word was heard from Warmbier. His parents, Fred and Cindy Warmbier of Wyoming, pushed the Obama administration to win his release, but all efforts failed. When Trump took office, he sent an envoy to North Korea to bring Warmbier home. The Kim government released him as a humanitarian gesture.

But Warmbier returned to Cincinnati in a state doctors diagnosed as “unresponsive wakefulness” that left him blind, paralyzed, bedridden and unable to communicate. Tests showed his brain had been starved of oxygen. He died six days after his return to Cincinnati at 22.

In December, Warmbier’s parents won a $501 million judgment against the North Korean government for their son’s wrongful death by torture. At Thursday’s news conference, Trump said nothing about any U.S. efforts to help the family collect on the judgment. Instead he simply called them “an incredible family.”

This is a developing story and will be updated.