SEOUL — A US national has been detained in North Korea after crossing the border, a UN body says.

The United Nations Command, which operates the Demilitarized Zone and joint security area (JSA), said the man did not have authorization.

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

BBC News has contacted the US Department of State for comment.

The KPA is the Korean People's Army, North Korea's military. The Demilitarized Zone (DMZ) separates the two Koreas and is one of the most heavily fortified areas in the world.

It is filled with landmines, surrounded by electric and barbed wire fencing and surveillance cameras. Armed guards are supposed to be on alert 24 hours a day.

Dozens of people try to escape North Korea every year, fleeing poverty and famine, but defections across the DMZ are extremely dangerous and rare.

The last time a soldier defected at the JSA was in 2017, when a North Korean soldier drove a vehicle, then ran by foot across the military demarcation line, South Korea said at the time.

The soldier was shot at 40 times, but survived.

Before the pandemic more than 1,000 people fled from North Korea to China every year, according to numbers released by the South Korean government.

There are currently six South Koreans in custody in North Korea.

Relations between the US and the north plummeted in 2017 after a US student who had been arrested a year earlier for stealing a propaganda sign was returned to the US in a comatose state and later died.

Three US citizens were later freed during Donald Trump's presidency in 2018. — BBC