The soldier was observed running toward North Korea and being taken in to custody, said a person familiar with the incident who, like others quoted for this story, was granted anonymity to speak openly.
The U.S. has already spoken with South Korea about the incident and plans to coordinate with Sweden, the U.S.'s interlocutors with North Korea, the same person said.
The junior enlisted soldier was due to face disciplinary action by the U.S. military, a DOD official said.
The soldier has not yet been named. His parents are located in the United States.
“This creates a significant diplomatic problem between North Korea and the U.S., and as has been noted, we are not in communication,” Rep. Adam Smith (D-Wash.), the House Armed Services Committee’s ranking member, told CNN based on early reports. “The first step is going to be reestablishing those communications, but if a U.S. soldier is in North Korean custody, we need to do what we can to get him back.”
The U.S. soldier’s crossing and detention comes amid escalating tension between the U.S. and North Korea over North Korea’s continued missile launches in the direction of neighboring South Korea and Japan. The incident occurred the same day that the USS Kentucky, a submarine armed with nuclear ballistic missiles, arrived in Busan, South Korea, for a scheduled port visit.
American officials say the deployment of the submarine is part of its “extended deterrence” policy.
“This port visit to Busan reflects the United States’ ironclad commitment to the Republic of Korea for our extended deterrence guarantee, and complements the many exercises, training, operations, and the other military cooperation activities conducted by Strategic Forces to ensure they are available and ready to operate around the globe at any time,” U.S. Forces Korea said in a news release Tuesday.
North Korean officials warned the U.S. on Monday against “foolish” actions. Workers Party official Kim Yo Jong, the sister of North Korean leader Kim Jong Un, said through state media that North Korea had launched a “military offensive” in response to U.S. aggression.
Joe Gould contributed to this report.