US soldier Travis King certainly made an impression during his time in South Korea.

Private Second Class King was being escorted to Seoul's airport this week, due to fly to Texas, after a drunken bar brawl, an altercation with police, and a stint in South Korean jail.

But instead of getting on the plane to face disciplinary hearings at Fort Bliss, King slipped away, joined a tourist tour of the Demilitarised Zone, and fled across the border. He is now believed to be in North Korean custody.

His family say they are "shocked" by his actions, which they have described in media interviews as out of character.

They said King, reported to be 23 years old, had struggled with being far from home and was grief-stricken after the death of a young cousin earlier this year.

But Seoul police told AFP King had a history of run-ins with the law -- punching a Korean national when drunk in a nightclub district in September last year, then attacking a police car in October when officers sought to detain him over a separate incident.

The young soldier "aggressively kicked the door (of the police car)" while shouting obscenities, the police officer said, causing 584,000 won ($461) of damage to the vehicle.

The incident resulted in a five million-won ($3,955) fine, the Yonhap News Agency reported, which King did not pay, leading to a two-month stint in jail.

Released from prison on July 10, King was taken to Seoul's Incheon Airport on Tuesday but his escorts couldn't accompany him beyond the security checkpoint, creating an opening for escape.

"At the gate, he approached an American Airlines official and reported that his passport was missing, and was able to return out of the departure gate," an airport official told The Korea Times.

- DMZ tour -

Experts told AFP that King's sprint across the border appeared to have been done "impulsively" but some level of planning was required for him to book a tour of the Joint Security Area (JSA).

The area, also known as Panmunjom, is administered by the United Nations Command and all visitors must provide passport details for background checks. Tourist trips typically sell out weeks in advance.

In May, King booked two different DMZ tour dates, according to US site The Messenger, including the July 18 one he eventually attended, using a private company called Hana Tours ITC.

The company, which according to their website organises DMZ trips for both tourists and US military based in South Korea, told AFP they had "nothing to say" and referred questions to the United States Army in Korea and the UN Command.

Some 27,000 US soldiers are based in South Korea, a key US regional security ally, which relies on Washington for a security guarantee to protect it from the nuclear-armed North.

The two Koreas remain technically at war and most of the shared border is heavily fortified, including with minefields. Inside the JSA, however, the border is marked only by a low concrete divider.

When King crossed it, he initially tried to enter Panmungak Hall, a North Korean building, but, finding the door locked, he ran to the back of the facility and was hurried into a van and driven away by North Korean guards, a US official told CNN.

- 'Wrong choice' -

Army spokesperson Bryce Dubee told US media King was a cavalry scout who enlisted in January 2021 and had no record of combat deployment.

His rank of private second class after more than two years of service suggested King may have been held back for disciplinary issues, Military.com said, because promotion to private first class is automatic after 12 months.

King's family said he had been struggling with being far from home. His uncle Carl Gates told The Daily Beast the illness and eventual death of his son, King's cousin, had "affected Travis a lot".

"Because he couldn't be here. He was in the Army, overseas," he said.

King had "loved and cherished" his cousin, Gates said, and "started being reckless and crazy" when he died earlier this year.

Former high-ranking North Korean official Thae Yong Ho, who is now a lawmaker in the South, said King will "soon find out that he made the wrong choice" in going to the North.

It will be particularly difficult for Washington to seek consular access to King, he said, because nearly all foreign embassies in Pyongyang withdrew foreign staff after North Korea closed its borders in 2020 due to the Covid-19 pandemic.

That includes Sweden, which handles US consular affairs in the North Korean capital.

AFP