The South Korean military announced on Sunday that a rare defection to North Korea had occurred across the strongly defended border. After identifying the person at 9:20 p.m. (1220 GMT) on Saturday on the eastern side of the Demilitarized Zone (DMZ) between the two Koreas, the Joint Chiefs of Staff (JCS) said it conducted a search operation. "We've confirmed that the guy crossed the Military Demarcation Line border and defected to the north at 10:40 p.m. (1340 GMT)," the JCS added. The JCS said it couldn't determine whether the person was still alive, but requested protection from the North via a military hotline. The unlawful border crossing occurred as North Korea has implemented strong anti-coronavirus efforts since closing its borders in early 2020, albeit no infections have been confirmed. After North Korean military shot and killed a South Korean fisheries officer who went missing at sea in September 2020, a public and political outcry erupted, for which Pyongyang blamed anti-virus rules and apologized. After a North Korean defector with COVID-19 symptoms illegally crossed the border into the North from the South two months prior, North Korean leader Kim Jong Un proclaimed a national emergency and locked off a border town. The number of North Korean defectors arriving in the South has also reached an all-time low as a result of the North's lengthy lockdowns and limitations on inter-provincial transit. Cross-border relations have deteriorated since Pyongyang and Washington failed to reach an agreement on denuclearization in 2019. Since the 1950-1953 Korean War concluded in an armistice rather than a peace treaty, South Korea and a United Nations army commanded by the United States are still formally at war with North Korea.