A senior North Korean official said in an interview published Thursday that his government lavished medical care on an ailing Otto Warmbier, and that President Trump, “a pathetic man with a big mouth,” is using Warmbier's death to foster hatred at a delicate moment in U.S.-North Korean relations.

“Our doctors and nurses made immeasurable efforts to save him and recover his health. Those treatments, all the money for nursing,” Choe Kang-il, a senior Foreign Ministry official, told the New York Times.

The interview with columnist Nicholas Kristof, an experienced Asia hand for the Times, was published as Warmbier’s parents, Fred and Cindy, have been visiting with lawmakers in Washington to urge the U.S. government to name North Korea officially as a state sponsor of terrorism.

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Last week, the Warmbiers appeared on Fox News and CNN to describe the condition of their son’s body when he returned to Cincinnati in June after more than 18 months in North Korea. In December 2015, Otto Warmbier, a Wyoming High School graduate studying at the University of Virginia, had traveled to the reclusive, repressive nation on a weeklong tour.

Immediately after the Warmbiers’ appearance on Fox News, President Trump posted on Twitter that Otto Warmbier had been tortured. In the interview with the Times, Choe said his government was surprised by the comment.

“We were startled when Trump, the president of the United States, tweeted the nonsense that Warmbier was systematically tortured. How can he write such things as president? Based on this tweet, I think Trump is a crazy man. He acts like a thug. Politics aside, he’s just a pathetic man with a big mouth.”

The exchanges over Warmbier's body are taking places as relations between the United States and North Korea are worsening over the Asian nation's nuclear ambitions. Trump has taken to belittling North Korea's leader, Kim Jong Un, as "Little Rocket Man."

As he was about to get on an airplane to return to the United States, Otto Warmbier was arrested and charged with stealing a poster out of a hotel in the North Korean capital of Pyongyang. He was held in custody, subjected to a one-hour show trial, convicted and sentenced in March 2016 to 15 years at hard labor then forced to read a propaganda statement that the process had been fair.

A short time after his sentencing, Warmbier suffered brain damage that left him in bedridden and unresponsive. His parents were not permitted to see him, and the North Koreans refused a visit from the Swedish ambassador to North Korea, who represents U.S. interests there.

He was held there without another word until June, when the North Korean government sent him home as a humanitarian gesture. He arrived in Cincinnati June 13, and doctors at the University of Cincinnati concluded that he was brain damaged beyond recovery. His family withdrew nutrition and kept him sedated until he died June 19.

At the time, the North Korean government has said Warmbier suffered botulism poisoning then took a sleeping pill. The UC doctors said they could not determine whether that story was true. Last week, Hamilton County Coroner Dr. Lakshmi Sammarco said the postmortem examination of Warmbier’s body found that he had not suffered from bedsores.

In the interview published Thursday with the Times, Choe did not provide more details about how Warmbier ended up in a state of what doctors now call “unresponsive wakefulness.”

Choe said Warmbier received excellent care while he was ill. “The summer in our country is very hot. If you lay down for a while, you’ll get bed sores on your back. It’s common sense.”

Kristof interjected, using the acronym for North Korea: “Here’s a healthy young man who visits the DPRK, commits a crime, and ends up in a coma, in a vegetative state, on your watch.”

Choe retorted, “The United States is known as the most advanced country in medicine. Warmbier died six days after he returned there. To us, to me, it’s a mystery.”

Kristof asked how Americans can believe North Korea’s explanation when the government refused to allow his parents or the Swedish envoy to North Korea visit him.

“The United States administration or some people with a certain intention let him die,” Choe replied. “This must be intended to foster and spread anti-communist hatred within America.”