Otto Warmbier's family speaks out against Trump's defense of Kim Jong Un in son's death The president defended Kim Jong Un in Hanoi on Thursday.

The parents of Otto Warmbier, the 22-year-old American student who died after 18 months of imprisonment in North Korea, spoke out Friday against President Donald Trump's defense of Kim Jong Un at this week's summit, when he said he believed Kim's claim he didn't know Warmbier had been tortured.

"We have been respectful during this summit process. Now we must speak out," Fred and Cindy Warmbier said in a statement.

"Kim and his evil regime are responsible for the death of our son Otto. Kim and his evil regime are responsible for unimaginable cruelty and inhumanity. No excuses or lavish praise can change that."

Several hours later, on Friday afternoon, Trump tweeted that he had been "misinterpreted" and that "Of course I hold North Korea responsible ... for Otto's mistreatment and death." But notably, he didn't mention Kim by name.

The University of Virginia student had been on a tour of North Korea when he was arrested for tearing down a poster.

The president has repeatedly praised Kim as "very smart" and a "real leader," even saying at a West Virginia rally after the first summit that the two "fell in love."

And on Thursday in Hanoi, despite having publicly supported the Warmbier family previously, Trump said he believed the dictator who runs North Korea's ruthless regime didn't know Warmbier was being tortured.

"I don't believe that he would have allowed that to happen," Trump said of Kim Jong Un. The president relayed what he said Kim had told him -- that Kim "didn't know about it" -- and said he would "take [Kim] at his word."

"He felt badly about it," the president said at a post-summit news conference. "He knew the case very well, but he knew it later," Trump added.

White House counselor Kellyanne Conway furthered the president's comments Friday on Fox News and responded to the Warmbiers' statement.

"The president agrees with the Warmbier family and holds North Korea responsible for Otto Warmbier's death. He's said that time and again," Conway said. "What the president is saying is that there is no indication Chairman Kim knew what happened to Otto Warmbier when it happened. It was after he was returned here to the United States that we all learned of his very sad and frankly unforgivable state."

Conway's comments, like the president's, separate Kim from what happened under his regime – despite the show trial Otto was subjected to in a North Korean courtroom which was then used as a propaganda tool for the regime.

His appearance in that courtroom would be the last time the Warmbiers saw their son before he was flown back to the U.S. in a coma.

The Warmbiers sued the North Korean government for more than a $1 billion late last year, saying U.S. officials had publicly confirmed that North Korea tortured their 22-year-old son. As proof, the family cited a tweet from Trump in response to an interview they did with Fox News. "Otto was tortured beyond belief by North Korea," Trump tweeted in September of 2017.

Otto, who died just six days after being brought back to the U.S., returned to his home state of Ohio blind, deaf and "jerking violently and howling," according to the lawsuit. Otto's lower teeth looked as if they'd been rearranged by a pair of pliers, the court documents said.

When the Warmbier's testified in federal court in December, it was about six months after Trump's first summit with North Korea's Kim. The family had, at that point, established a close relationship with the president, who was adamant that Otto "did not die in vain."

About a month later, Otto's parents Cindy and Fred attended Trump's 2018 State of the Union address and stood, rife with grief, to a standing ovation as the president denounced North Korea's brutal treatment of their son.

"You are powerful witnesses to a menace that threatens our world, and your strength inspires us all. Tonight, we pledge to honor Otto’s memory with American resolve," Trump said.

Two weeks later, Otto's father Fred traveled as a guest of Vice President Mike Pence to attend the Olympics in South Korea.

While there, Warmbier met with a group of North Korean defectors to put a spotlight on the country’s alarming human rights record -– an issue Trump has rarely mentioned in his denuclearization negotiations with Kim.

“It's hard -- evil is hard to accept,” Warmbier told the group. “And I've experienced evil, and you have, too. And I just feel so much love and warmth for you all. And I just can't tell you how proud I am to be here with you.”

But Friday's statement presented a sharp contrast to the Warmbier's attendance at the State of the Union speech and the trip to South Korea with Pence, reflecting the difference the past year has made.

Pence, who spoke about North Korea at a conservative political conference on Friday morning about an hour after Otto's family had released their statement, made no mention of Warmbier or his parents during his speech -- though he did cite progress the Trump administration has made with the country, including the return of U.S. hostages.

ABC News' Jordyn Phelps and Adam Kelsey contributed to this report.