A tour agency that took Otto Warmbier into North Korea before he was detained for 18 months has said it will stop taking Americans into the reclusive state.

Mr Warmbier, a student from the United States, died on Monday after he was repatriated back to his family in Ohio suffering from severe brain damage.

Young Pioneer Tours, an agency operated largely by expats in the north Chinese city of Xi’an, had previously described North Korea as "probably one of the safest places on Earth to visit.”