Student’s death ‘a mystery’

North Korea says the death of America university student Otto Warmbier soon after his return home was a mystery, and has dismissed accusations that he died because of torture and beating during his captivity as ‘‘groundless’’.

North Korea’s foreign ministry spokesman said yesterday Warmbier was ‘‘a victim of the policy of strategic patience’’ of former United States president Barack Obama, whose government never requested his release, according to comments carried by the official KCNA agency.

‘‘The fact that Warmbier died suddenly in less than a week just after his return to the US . . . is a mystery to us as well,’’ the KCNA quoted the spokesman as saying.

Warmbier, 22, was arrested while visiting the reclusive country as a tourist. He was sentenced to 15 years’ hard labour for trying to steal an item bearing a propaganda slogan from his hotel, North Korean state media said.

He was sent home last week suffering from brain damage and in what US doctors called a state of unresponsive wakefulness. He died on Tuesday.

Katina Adams, a spokeswoman for the US State Department’s East Asia Bureau, said Washington had repeatedly requested the release of Warmbier under the Obama administration.

A former senior State Department official said the US had made repeated requests for Warmbier’s release on humanitarian grounds under Obama, including via the North Korean mission at the United Nations, via the Swedish mission in Pyongyang, at unofficial talks with North Korean officials involving former US officials, and via third parties.

Warmbier’s death has fanned a conflict between North Korea and the US that was already aggravated by North Korea’s defiant missile launches and two nuclear tests since early last year as part of its efforts to build a nuclear-tipped intercontinental ballistic missile capable of hitting the US mainland.

The North’s foreign ministry spokesman said there was a smear campaign to slander North Korea, which had given ‘‘medical treatments and care with all sincerity’’ to a person who was ‘‘clearly a criminal’’.