Cynthia Warmbier, the mother of Otto Warmbier, the American student who died in 2017 after being imprisoned for months in North Korea, said on Friday that diplomacy with its leader, Kim Jong-un, was a “charade” and likened Mr. Kim’s regime to “absolute evil.”

“It’s obvious to the world that we’re on to him,” she said of Mr. Kim. “But unless we keep the pressure on North Korea, they are not going to change, and I’m very afraid that we are going to let up on this pressure.”

She added: “There’s a charade going on right now. It’s called diplomacy. How can you have diplomacy with someone that never tells the truth? That’s what I want to know. I’m all for it, but I’m very skeptical.”

She made the comments at the Hudson Institute in Washington, where she sat on a panel during a seminar on the “abduction of Japanese, South Korean, American and nationals of other countries by North Korea,” according to the institute.