An American national is in North Korean custody after crossing the heavily fortified border from South Korea, the UN Command has said.
The US citizen was on a tour to the Korean border village of Panmunjom when he crossed into the North without authorisation, the American-led command overseeing the area said on Tuesday.
The group said it is working with its North Korean counterparts to resolve the incident.
It did not say who the man is or why he crossed the border.
Cases of Americans or South Koreans defecting to the North are rare, though more than 30,000 North Koreans have fled to the South to avoid political oppression and economic difficulties since the end of the 1950-53 Korean War.
Panmunjom, which is inside the 154-mile-long Demilitarised Zone (DMZ), was created at the end of the Korean War.
Bloodshed and gunfire have occasionally occurred there but it has also been a venue for numerous talks and a popular tourist spot.
The area is jointly overseen by the UN Command and North Korea.
In November 2017, North Korean soldiers fired 40 rounds as one of their colleagues ran towards freedom.
The soldier was hit five times before being found under a pile of leaves on the southern side of Panmunjom.
He survived and is now in South Korea.
No civilians live in Panmunjom.
There have been a small number of US soldiers who fled to North Korea during the Cold War, including Charles Jenkins, who deserted his army post in South Korea in 1965 and fled across the DMZ.
He appeared in North Korean propaganda films and married a Japanese nursing student abducted by North Korean agents. He died in Japan in 2017.
In recent years, some Americans have been arrested in North Korea after allegedly entering the country from China. They were later convicted of espionage and other anti-state acts but were often released after the US sent high-profile missions to secure their freedom.
In 2018, North Korea released the last three known American detainees as North Korean leader Kim Jong Un was engaged in nuclear diplomacy with then-president Donald Trump.
The high-stakes diplomacy collapsed in 2019 amid wrangling over US-led sanctions on North Korea.
Tuesday’s border crossing happened amid high tensions over North Korea’s barrage of missile tests since the start of last year.
The US earlier on Tuesday sent a nuclear-armed submarine to South Korea for the first time in decades as deterrence against North Korea.