North Korea again refuted allegations Otto Warmbier was tortured while imprisoned in the isolated dictatorship for more than a year, according to reports published Thursday.

A statement released via state-broadcaster KCNA referred to President Donald Trump as an "old lunatic," according to the French news agency AFP.

North Korea accused the US of "luring and pushing" Otto Warmbier into breaking the country's laws, the country's foreign ministry reportedly said in a statement.

"Trump and his clique, for their anti-DPRK propaganda, are again exploiting the death of Otto Warmbier, an American college student who had been under reform through labour for the criminal act he committed against the DPRK and died after returning to the US," according to the statement, referring to its acronym for Democratic People's Republic of Korea.

Warmbier, a native of the Cincinnati suburb of Wyoming, died after being imprisoned by the North Korean government for 17 months for stealing a sign. Warmbier, 22, was evacuated in a coma on June 13. He was returned home to his family in Cincinnati, where he died less than a week later.

The comments came after Hamilton County Coroner Lakshmi Sammarco said that Warmbier had died from a lack of oxygen to the brain. Sammarco's report contradicted statements made by the Warmbier's parents in an interview with Fox & Friends on Tuesday.