North Korea did not answer a daily phone call from South Korea at the inter-Korean liaison office on Monday, for the first time since its opening in 2018.

South Korean Unification Ministry spokesperson Yoh Sang-key said Seoul will attempt another call in the afternoon and monitor the situation. The spokesperson added that Seoul remains committed to fulfilling all inter-Korean agreements and cooperating with Pyongyang for peace and prosperity on the Korean Peninsula.

The North's lack of response comes after it threatened to shut down the joint Gaeseong Industrial Complex, the liaison office and abandon military tension-easing deals in protest of anti-Pyongyang leaflet campaigns in the South.

Since the office's opening in September 2018 following the historic Panmunjeom inter-Korean summit, the two Koreas have made two daily calls, one at 9:00 a.m. and another at 5:00 p.m.

Defense ministry officials, meanwhile, said the inter-Korean military hotlines remain in normal operation.