Otto Warmbier, an American college student who was released by North Korea in a coma last week after more than a year in captivity, died on Monday, his family said.
The 22-year-old "has completed his journey home", the family said in a statement.
"Unfortunately, the awful, torturous mistreatment our son received at the hands of the North Koreans ensured that no other outcome was possible beyond the sad one we experienced today," his parents said.
Doctors had described his condition as a state of "unresponsive wakefulness" and said he suffered a "severe neurological injury" of unknown cause.
President Donald Trump called North Korea a "brutal regime" after the death was announced.
Mr Trump said: "Lot of bad things happened but at least we got him home to be with his parents."
His father, Fred Warmbier, said last week he believed Otto had been fighting for months to stay alive to return to his family.
Their statement on Monday said he had looked uncomfortable and anguished after returning June 13, but his countenance later changed.
"He was peace. He was home, and we believe he could sense that," they said.
Mr Warmbier was convicted of subversion after he tearfully confessed that he had tried to steal a propaganda banner while visiting with a tour group from China.
He was sentenced to 15 years in prison with hard labour in North Korea.
The University of Virginia student was held for more than 17 months.
His family said last week they were told he had been a coma since soon after his March 2016 sentencing.
Doctors said he has suffered extensive loss of brain tissue and "profound weakness and contraction" of his muscles, arms and legs.
His eyes opened and blinked, but without signs of understanding verbal commands or his surroundings.
North Korea said he went into a coma after contracting botulism and taking a sleeping pill.
Doctors in Cincinnati said they found no active sign of botulism nor evidence of beatings.
His parents said in a statement on the day of his release that they wanted "the world to know how we and our son have been brutalised and terrorised by the pariah regime" and expressed relief he had been returned to "finally be with people who love him".
Fred Warmbier praised his son's "performance" and Mr Trump's administration.
He was critical of former President Barack Obama's approach to his son's situation.
Otto Warmbier grew up in the northern Cincinnati suburb of Wyoming.
He won an award at the highly rated high school, and was on the soccer team, among other activities.
Three Americans remain held in North Korea.
The US government accuses North Korea of using such detainees as political pawns.
North Korea accuses Washington and South Korea of sending spies to overthrow its government.
At the time of Mr Warmbier's release, a White House official said Joseph Yun, the US envoy on North Korea, had met with North Korean foreign ministry representatives in Norway the previous month.
Such direct consultations between the two governments are rare because they do not have formal diplomatic relations.
At the meeting, North Korea agreed Swedish diplomats could visit all four American detainees.
Mr Yun learned about Mr Warmbier's condition in a meeting a week before the release from the North Korean ambassador at the UN in New York.
Mr Yun then was dispatched to North Korea and visited Mr Warmbier on June 12 with two doctors and demanded his release on humanitarian grounds.