President Trump said Thursday he spoke to North Korean leader Kim Jong Un about the death of American college student Otto Warmbier following his imprisonment in North Korea but does not believe Kim was aware of Warmbier’s captivity and ill treatment.

“In those prisons and camps, you have a lot of people, and some really bad things happened to Otto,” Trump told reporters during a press conference following the abrupt end of his summit with Kim in Hanoi, Vietnam, after the Washington Post’s David Nakamura asked the president if he’d confronted Kim about Warmbier’s death. “Some really, really bad things. But [Kim] tells me that he didn’t know about it, and I will take him at his word.”