A US man is believed to be in custody in North Korea after he crossed the border without permission during a tour.

His identity has not been officially confirmed but South Korean newspaper Dong-a Ilbo said he is a US Army solider named Travis King.

It happened as the man was visiting the Joint Security Area, part of the demilitarised zone separating South and North Korea.

“A U.S National on a JSA orientation tour crossed, without authorization, the Military Demarcation Line into the Democratic People’s Republic of Korea (DPRK),” the UN Command tweeted.

“We believe he is currently in DPRK custody and are working with our KPA counterparts to resolve this incident,” it added.

South and North Korean forces face each other at the Joint Security Area and it’s often used for diplomatic meetings between the countries.

It is also a popular tourist spot.

In 2017, a North Korean soldier was gunned down by colleagues as he made a break for freedom across the JSA border.

He was hit five times but survived and now lives the South.

The US bans its citizens from entering North Korea – a notoriously secretive and totalitarian state run by Kim Jong Un.