News-Middle East-Korea: North Korea has ignored 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.

South Korea's Unification Ministry and Defense Ministry said on Tuesday that the North Koreans had left a regularly-scheduled call in the afternoon unanswered, even though they had answered one in the morning.

The two Koreas generally communicate over the hotline twice a day. They had agreed to rebuild trust two weeks ago by restoring the hotline, which had been offline for more than a year due to political acrimony.

The development came after Kim's powerful sister, Kim Yo-jong, accused South Korea of "perfidious behavior" for pushing ahead with "dangerous war exercises." The South Korea and the US are set to hold computer-simulated exercises next week, but preliminary training reportedly began on Tuesday.