The United States had previously said it was moving missile defense systems to Guam, a Western Pacific territory that is home to U.S. naval and air bases. North Korea has cited those bases when listing possible targets for missile attacks.
A symbol of cooperation at risk
The souring situation on the Korean Peninsula was in evidence in the failure of more than 50,000 North Korean workers to show up for work Tuesday morning at the Kaesong Industrial Complex, the manufacturing zone shared by the two Koreas that had operated without such an interruption for eight years.
The North had declared Monday that it would pull out its workers and temporarily suspend activities at the complex, which sits on its side of the heavily fortified border but houses the operations of more than 120 South Korean companies.
On Tuesday, the South Korean Unification Ministry said the North Korean workers hadn't reported for work in the district, which is the last major symbol of cooperation between the two Koreas.
Analysts had expressed skepticism that Pyongyang would follow through on previous threats to shut down the complex, noting that it is an important source of hard currency to Kim's regime.
The move also is likely to put pressure on the city of Kaesong itself, where the North Korean workers and their families live. With an estimated population of between 200,000 and 300,000 people, it is one of the impoverished country's largest cities.