Otto Warmbier, the US student released by North Korea in a coma after more than a year in detention, has died, his family said Monday. 

The 22-year-old, who had suffered severe brain damage, was medically evacuated to the United States on June 13. He died Monday at 2:20 pm (1820 GMT), surrounded by family at a hospital in his home town of Cincinnati. Ohio.  

"It is our sad duty to report that our son, Otto Warmbier, has completed his journey home," his family said in a statement.

"The awful torturous mistreatment our son received at the hands of the North Koreans ensured that no other outcome was possible," they added. 

Pyongyang said that Warmbier fell into a coma soon after he was sentenced in March last year for stealing a political poster from a North Korean hotel.