Otto Warmbier, the U.S. student released in a coma last week after nearly 18 months in detention in North Korea, died on Monday, June 19, prompting President Donald Trump to slam the "brutal regime" in Pyongyang, AFP reports.

The 22-year-old was medically evacuated to the United States last Tuesday, suffering from severe brain damage. He died six days later surrounded by relatives in his hometown of Cincinnati, Ohio.

"The awful torturous mistreatment our son received at the hands of the North Koreans ensured that no other outcome was possible," the family said in a statement announcing Warmbier's death.

Warmbier was on a tourist trip when he was arrested and sentenced in March last year to 15 years hard labor for stealing a political poster from a North Korean hotel, a punishment U.S. officials decried as far out of proportion to his alleged crime.

Trump slammed Pyongyang following news of his death.

"It's a brutal regime," he said during a White House event. "Bad things happened but at least we got him home to his parents."