
Kim Dong-Chul, a 62-year-old naturalised us citizen born in South Korea, was arrested last October.
Last month, Kim made an apparent confession in Pyongyang, saying he was paid by South Korean intelligence officers.
The US has previously accused North Korea of using its citizens as pawns in a diplomatic game. Pyongyang denies the accusations.
In March, US student, Otto Frederick Warmbier, was jailed for 15 years for stealing a propaganda sign and “crimes against the state”.