The last time there was a defection at the JSA was in 2017, when a North Korean soldier drove a military jeep then ran on foot across the demarcation line at Panmunjom.
He was shot multiple times by his fellow North Korean soldiers as they sought to prevent his escape, but after hours of surgery, he survived.
“Panmonjom is the most likely site this American chose to cross into North Korea because it’s the only location one could attempt such a move out of the whole JSA tour,” Choi Gi-il, a professor of military studies at Sangji University told AFP.
NUCLEAR SUB
The apparent defection comes as relations between the two Koreas are at one of their lowest points ever, with diplomacy stalled and North Korean leader Kim Jong Un calling for increased weapons development, including tactical nuclear weapons.
Seoul and Washington have ramped up defence cooperation in response, staging joint military exercises with advanced stealth jets and US strategic assets.
On Tuesday, the allies held the first Nuclear Consultative Group (NCG) meeting in Seoul, which aims to improve nuclear coordination and boost military readiness against North Korea.
“As we speak, an American nuclear submarine is making port in Busan today, the first visit of American nuclear submarine in decades,” White House Indo-Pacific coordinator Kurt Campbell told reporters after the meeting.
The last time Washington deployed one of its nuclear-capable submarines to South Korea was in 1981.
Washington announced it would deploy a submarine capable of launching ballistic missiles with nuclear warheads to the Korean peninsula in April, while South Korean President Yoon Suk Yeol was on a state visit. It did not specify a timeline.
The move is likely to trigger a strong response from the North, which baulks at having US nuclear assets deployed around the Korean peninsula.
Kim Yo Jong, the powerful sister of leader Kim Jong Un, said on Monday that such actions would only “make the (Democratic People’s Republic of Korea) go farther away” from possible talks.