NKorea 'brutal' after student dies: Trump

US President Donald Trump has called North Korea a "brutal regime" following the death of 22-year-old college student Otto Warmbier, who had been serving a 15 year jail sentence for trying to steal a propaganda banner while visiting the reclusive state.

"Lot of bad things happened but at least we got him home to be with his parents," Trump said.

Warmbier was released by North Korea last week after being held for more than 17 months. He was in a coma.

His family said in a statement that "the awful torturous mistreatment our son received at the hands of the North Koreans" meant that "no other outcome was possible beyond the sad one we experienced today."

Warmbier was sentenced to 15 years in prison with hard labour in North Korea, convicted of subversion after tearfully confessing to trying to steal the banner.