The U.S. military was scrambling to establish the fate of an American soldier who made an unauthorised crossing of the inter-Korean border into North Korea, throwing Washington into a new crisis in its dealing with the nuclear-armed state.

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

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

North Korea has been testing increasingly powerful missiles capable of carrying nuclear warheads, including a new solid-fuel intercontinental ballistic missile last week.

Colonel Isaac Taylor, a spokesperson for U.S. Forces Korea, said the military was “working with our KPA counterparts to resolve this incident,” referring to North Korea’s People’s Army.

The U.N. Command (UNC), which oversees security for the border area, had used hotlines to communicate with the North Koreans about the incident, Taylor said, but did not give details.

“We communicate with the North Koreans every single day,” he said. “It’s all part of the armistice agreement.”

North Korea fires missiles

The soldier was on a tour of the Panmunjom truce village with other visitors when he crossed a Military Demarcation Line, U.S. officials say. The heavily defended border has separated the two Koreas since the Korean War ended in 1953 with an armistice.

U.S. officials were stumped why the soldier fled to the North and outlined a puzzling series of events.

King had finished serving time in detention in South Korea for an unspecified infraction and was transported by the U.S. military to the airport to return to his home unit in the United States, two U.S. officials said.

He had already passed alone through security to his gate, then decided to flee, one official said. Civilian tours of the demilitarized zone (DMZ) are advertised at the airport and King appeared to have decided to join one, an official said.

The two U.S. officials, who spoke on condition of anonymity, said the soldier had been due to face disciplinary action by the U.S. military. But he was not in custody at the time he decided to flee, one of them said.

South Korea’s Unification Ministry, which handles ties with the North, said all tours to Panmunjom had been cancelled indefinitely at the U.N. Command’s request. But Imjingak in Paju that marks the end of the road before the military-controlled bridge leading into the DMZ was bustling with tourists.

It was unclear how long North Korean authorities would hold the soldier but analysts said the incident could be valuable propaganda for the isolated country.

Before dawn on Wednesday, North Korea fired two ballistic missiles from an area near its capital, Pyongyang, flying 550 km and 600 km before plunging into the sea off its east coast.

The launch came hours after the South Korea and the United States held the first round of talks on Tuesday on upgrading coordination in the event of a nuclear war with North Korea.

The United States has pledged to deploy more strategic assets such as aircraft carriers, submarines and long-range bombers to South Korea, drawing an angry response from Pyongyang which vowed to escalate its own military response.

A former North Korean diplomat who defected to the South said King may be a propaganda tool for North Korea and a loss of face for the United States on the day of the arrival of the submarine and the nuclear talks.

“But looking at previous cases of U.S. servicemen who went into the North, holding an American solder is probably a not very cost-effective headache for the North in the long run,” said Tae Yong-ho, who is a member of South Korea’s parliament.