The president plans to meet with Kim Jong Un in February to try to coax the North to give up its nuclear program.
According to South Korea's spy agency, Jo Song Gil and his wife went into hiding in November. A defection would embarrass leader Kim Jong Un.
In a tightly controlled event, about 200 South Koreans and their family members cross into North Korea for three days of meetings with their northern relatives.
North Korea cancels a high-level meeting with South Korea and threatens to scrap next month's historic summit over military exercises between Seoul and Washington.
Analysts say that while the closure of the nuclear test site is important, it doesn't represent a material step toward full denuclearization.
The North Korean leader tells Seoul he'd be willing to give up nuclear weapons if the U.S. commits to a formal end to the Korean War and pledges not to attack the North.
China's sustained game of hardball on trade may have been the decisive factor behind North Korean leader Kim Jong Un's diplomatic overtures to Seoul and Washington.
An armored train traveling between North Korea and Beijing prompts conjecture about a visit by North Korean leader Kim Jong Un or another high-level official.
President Moon Jae-in says that despite North Korea’s recent outreach to Seoul and Washington, many “critical moments” still lie ahead in the effort to end the nuclear crisis.
South Korean envoys plan to meet with Kim Jong Un on a rare two-day visit to Pyongyang that's expected to focus on how to ease a standoff over North Korea's nuclear ambitions.