North Korea ignores a hotline call from South Korea, Seoul says, hours after North Korean leader Kim Jong-un's sister warned the South and the US over annual joint military exercises, and shortly after the two Koreas agreed to reestablish the emergency communication line.

North Korean leader Kim Jong-un has mobilized the military to carry out relief work in areas recently hit by floods.

A South Korean official says the coronavirus pandemic threatens the joint military exercises with the United States, as the two sides struggle to agree on the scale, scope and timing of their annual war games.