In 2014, another US citizen was arrested by South Korean soldiers for allegedly trying to swim across a river to North Korea. The soldier was in serious condition at a South Korean hospital on Wednesday following two rounds of surgeries.
The presidency has changed since, from the former Park Geun-hye administration to the incumbent Moon Jae-in's, but the tension is continuing to build up with North's reluctance to denuclearize and come forward for dialogue.
The drill involves 21 vessels - including 14 from the United States and seven from South Korea, with the latter equipped with the Aegis Combat System which allows them to track and guide weapons to destroy enemy targets.
In this September 28, 2017, photo, a North Korean flag flutters in the wind atop a 160-meter (525-foot) tower in the North's Kijong-dong village near the truce village of Panmunjom in the Demilitarized Zone which has separated the two Koreas since the Korean War, in Paju, South Korea.
The official said the South's soldiers heard a gunshot and then retrieved the unarmed and bleeding soldier in the mid-afternoon.
Seoul: N. Koreans Fired At Soldier As He Defected To South
The Kaesong Industrial Complex, the industrial park where the two Koreas ran collaborative business models, was shut down on February 10, 2016 by the South Korean government, in response to the North's nuclear and ballistic missile tests. The DMZ, created at the end of the 1950-53 Korean War, serves as a de facto border between the Koreas.
"Currently, there are no unusual signs in the North Korean military, but we are increasing alertness against the possibility of North Korean provocations", officials said.
The solider was found beneath a pile of leaves on the southern side of the JSA and South Korean troops crawled there to recover him. More than a million mines are believed to be buried inside the zone.
American presidents often visit Panmunjom and other DMZ areas during their trips to South Korea to reaffirm their security commitment to the South. President Donald Trump planned to visit the DMZ to underscore his stance against North Korea's nuclear program when he came to South Korea last week as part of an Asian tour, but his plans were thwarted by heavy fog that prevented his helicopter from landing at the border area. They stand only several meters (yards) away from tall South Korean soldiers wearing aviator sunglasses standing motionless like statues. South Korean media described him as a 29-year-old computer repairman from Texas who hoped to meet North Korean leader Kim Jong Un.
Three enormous aircraft carriers, the USS Ronald Reagan, USS Theodore Roosevelt and USS Nimitz, are pictured alongside their strike forces and a range of fighter jets as the vessels patrol the seas off the North Korean coast. In 1998, a North Korean solider fled to South Korea via Panmunjom.