SEOUL – The US military was scrambling on Wednesday to determine the fate of an American soldier who made an unauthorised crossing at the inter-Korean border into North Korea, throwing Washington into a new crisis in its dealings with the nuclear-armed state.

The US Army identified the soldier as Private Travis T. King, who joined in 2021 and was facing disciplinary action. While on an orientation tour of the Joint Security Area (JSA) on the border between the two Koreas, King crossed into North Korea on Tuesday “wilfully and without authorisation”, US Defence Secretary Lloyd Austin said.

“We believe that he is in (North Korean) custody and so we’re closely monitoring and investigating the situation and working to notify the soldier’s next of kin,” Mr Austin told a briefing.

North Korea’s state media has made no mention of the incident. Its mission to the United Nations in New York did not immediately respond to requests for comment.

“King was released on July 10 after serving around two months in a South Korean prison on assault charges,” a Seoul official told AFP.

South Korean police told AFP that King had been investigated for assault in September 2022, but was not detained at the time.

CBS News, citing US officials, reported that the soldier was being escorted home to the United States for disciplinary reasons, but managed to leave the airport and join the tour group.

The crossing comes at a time of renewed tension on the Korean peninsula, with the arrival on Tuesday of a US nuclear-armed ballistic missile submarine, and the test launch early on Wednesday of two ballistic missiles into the sea by North Korea.

North and South Korea remain technically at war as the 1950-1953 Korean War ended with an armistice rather than a peace treaty, with a demilitarised zone running along the border.

Soldiers from both sides face off at the JSA north of Seoul, which is overseen by the United Nations Command. It is also a popular tourist site, and hundreds of visitors tour the South Korean side each day.

Former US president Donald Trump met North Korean leader Kim Jong Un at the Panmunjom Truce Village in 2019 and even stood on North Korean soil after stepping across the demarcation line.

An eyewitness who said they were on the same JSA tour told CBS News the group had visited one of the buildings at the site when “this man gives out a loud ‘ha ha ha’ and just runs in between some buildings”.

“I thought it was a bad joke at first but, when he didn’t come back, I realised it wasn’t a joke and then everybody reacted and things got crazy.”

Hours later, North Korea fired two short-range ballistic missiles into the sea, according to the South Korean military – an apparent response to the arrival of the American nuclear-armed submarine in South Korea, the first such visit since 1981.

The launches were likely unrelated to the American soldier crossing the border “but such an incident doesn’t help matters”, said Dr Leif-Eric Easley, a professor at Ewha University in Seoul.

“The Kim regime is likely to treat a border crosser as a military, intelligence and public health threat even though it is more likely that such an individual is mentally distressed and acting impulsively due to personal issues.”

North Korea sealed its borders at the start of the Covid-19 pandemic in 2020 and has yet to reopen them. Its security presence on its side of the border at the JSA has also been scaled back significantly.

When AFP toured the JSA earlier this year, no North Korean guards were visible. Even so, under armistice protocols, South Korean or US personnel could not cross the border to retrieve the US national.

The incident comes as relations between the two Koreas are at one of their lowest points, with diplomacy stalled and Mr Kim calling for increased weapon development, including tactical nuclear warheads.

Seoul and Washington have ramped up defence cooperation in response, staging joint military exercises with advanced stealth jets and US strategic assets.

The JSA in Panmunjom is typically peaceful despite ongoing hostility between the two sides.

In 1976, two American soldiers were killed in the JSA by North Koreans with axes in a dispute over a tree.

The last time there was a defection at the JSA was in 2017, when a North Korean soldier drove a military jeep and then ran on foot across the demarcation line at Panmunjom.

He was shot multiple times by his fellow North Korean soldiers but survived.

In general, defections between the two Koreas are rare but far more common in the other direction, when North Koreans seek to escape grinding poverty and repression by fleeing, typically across the northern land border into China. REUTERS, AFP