U.S. President Donald Trump has condemned North Korea as a "brutal regime" after the death of a U.S. college student who had been incarcerated there for 17 months.
Pyongyang returned 22-year-old Otto Warmbier to the United States last week, saying he had been in a coma for a year.
Trump said Warmbier's death at a Cincinnati hospital on June 19 had deepened his administration's resolve "to prevent such tragedies from befalling innocent people at the hands of regimes that do not respect the rule of law or basic human decency."
In a statement, Warmbier's parents said Otto had been subjected to "awful torturous mistreatment at the hands of the North Koreans."
Warmbier was detained during a trip to North Korea in January 2016.
After a one-hour trial in March last year in which he confessed that he had tried to steal a propaganda banner, he was sentenced to 15 years in prison with hard labor for subversion.
North Korea said Warmbier contracted botulism, a rare illness that causes paralysis, after his trial, and had been in a coma since he was given a sleeping pill.
However, U.S. doctors said he had suffered a "severe neurological injury" of unknown cause.