SEOUL, South Korea — North Korea stayed silent Wednesday about the detention of an American soldier who sprinted across the Koreas’ heavily fortified border as other members of his tour group looked on in shock. Some observers said the North was unlikely to repatriate him anytime soon amid heightened tensions between the rivals.

Pvt. 2nd Class Travis King bolted into North Korea while on a tour of the Demilitarized Zone on Tuesday, a day after he was supposed to leave the country and travel to a base in the U.S. King was released from a South Korean prison earlier this month, not the first time he’d run into legal trouble in the country. He could have faced more punishment in the U.S.

King is the first known American held in North Korea in nearly five years. Each detention has set off complicated diplomatic wrangling, and this one comes at a time of heightened animosity. On Wednesday, North Korea test-fired two ballistic missiles into the sea in an apparent protest at the deployment of a U.S. nuclear-armed submarine in South Korea for the first time in decades.

“It’s likely that North Korea will use the soldier for propaganda purposes in the short term and then as a bargaining chip in the mid- to long term,” said Yang Moo-jin, president of the University of North Korean Studies in South Korea.

King, 23, was a cavalry scout with the 1st Armored Division who had served nearly two months in a South Korean prison for assault. He was released on July 10 and was supposed to leave Monday for Fort Bliss, Texas, where he could have faced additional military discipline and discharge from the service.

He was escorted as far as customs but left the airport before boarding his plane. It wasn’t clear how he spent the hours until joining the Panmunjom tour and running across the border Tuesday afternoon. The Army released his name and limited information after King’s family was notified. But a number of U.S. officials, speaking on condition of anonymity because of the sensitivity of the matter, provided additional details.

One woman who was on the tour with King said she initially thought his dash was some kind of stunt — and that she and others in the group couldn’t believe what happened.

King’s stint in prison was not the first time he faced legal trouble in South Korea.

In February, a court fined him 5 million won ($3,950) after being convicted of assaulting an unidentified person and damaging a police vehicle in Seoul last October, according to a transcript of the verdict obtained by The Associated Press.

The ruling said King had also been accused of punching a 23-year-old man at a Seoul nightclub, though the court dismissed that charge because the victim didn’t want King to be punished.

King’s mother told ABC News she was shocked when she heard her son had crossed into North Korea.

“I can’t see Travis doing anything like that,” Claudine Gates, of Racine, Wisconsin, said.

Gates said said she last heard from her son “a few days ago,” when he told her he would return soon to Fort Bliss. She added she just wanted “him to come home.”

US Working to Resolve Incident

White House press secretary Karine Jean-Pierre said that the U.S. government was working with its North Korean counterparts to “resolve this incident.” The American-led U.N. Command said Tuesday the U.S. soldier was believed to be in North Korean custody.

“We’re closely monitoring and investigating the situation,” U.S. Defense Secretary Lloyd Austin told a Pentagon news conference, noting he was foremost concerned about the soldier’s well-being.

It wasn’t known whether and how the U.S. and North Korea, which have no diplomatic relations, would communicate. In the past, Sweden, which has an embassy in Pyongyang, provided consular services for other Americans detained in North Korea. But Swedish diplomatic staff reportedly haven’t returned to North Korea since the country imposed a COVID-19 lockdown in early 2020 and ordered all foreigners to leave.

Some observers said North Korea and the U.S. could still talk via Panmunjom or the North Korean mission at the U.N. in New York.

Cases of Americans or South Koreans defecting to North Korea are rare, though more than 30,000 North Koreans have fled to South Korea to avoid political oppression and economic difficulties since a truce ended the 1950-53 Korean War.

Tae Yongho, a former minister at the North Korean Embassy in London, said North Korea is likely pleased to have “an opportunity to get the U.S. to lose its face” because King’s crossing happened on the same day the U.S. submarine arrived in South Korea. Tae, now a South Korean lawmaker, said North Korea was unlikely to return King easily because he is a soldier from a nation technically at war with North Korea and he voluntarily went to the North.

The United States and North Korea are still officially at war because the Korean War ended with an armistice, not a peace treaty. The U.S. still stations about 28,000 troops in South Korea, and tensions on the Korean Peninsula run high, with North Korea carrying out missile tests like Wednesday’s and the U.S. holding military drills with South Korea.

Panmunjom, located inside the 154-mile-long Demilitarized Zone, has been jointly overseen by the U.N. Command and North Korea since the close of the Korean War.

Bloodshed has occasionally occurred there, but it has also been a venue for diplomacy and tourism, drawing visitors who want to see the Cold War’s last frontier. No civilians live there, but North and South Korean soldiers face off while tourists on both sides snap photographs.

A small number of U.S. soldiers went 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 who had been abducted from Japan by North Korean agents. Jenkins died in Japan in 2017.

In recent years, some American civilians have been arrested in North Korea on allegations of espionage, subversion and other anti-state acts, but were released after the U.S. sent high-profile missions to secure their freedom.

In May 2018, North Korea released three American detainees who returned to the United States on a plane with then-Secretary of State Mike Pompeo during a short period of warm relations. Later in 2018, North Korea said it expelled American Bruce Byron Lowrance. Since his deportation, there have been no reports of other Americans detained in North Korea before Tuesday.

Those releases stood in striking contrast to the fate of Otto Warmbier, an American university student who died in 2017 days after he was released by North Korea in a coma after 17 months in captivity.

The United States, South Korea and others have accused North Korea of using foreign detainees to wrest diplomatic concessions. Some foreigners have said after their release that their declarations of guilt while in North Korean custody were made under coercion.

Sean Timmons, a managing partner at the Tully Rinckey law firm, which specializes in military legal cases, said if King is trying to present himself as a legitimate defector fleeing either political oppression or persecution, he would be dependent on North Korea’s leadership to decide if he can stay.

“It’s going to be up to the whims of their leadership, what they want to do,” Timmons said.