President Donald Trump said Kim Jong Un “felt very badly” about student Otto Warmbier, who was imprisoned in North Korea and died after being returned to the U.S. in a vegetative state in 2017.

Speaking at a press conference in Hanoi, Vietnam, on Thursday after the two leaders failed to reach a nuclear agreement, Trump said he believed Kim.

“Those prisons are rough, they’re rough places and bad things happened. But I don’t believe he knew about it,” Trump said. “He tells me he didn’t know about it and I will take him at his word.”