​North Korea test-fired hypersonic missiles ‌on Sunday, state ​media KCNA reported on Monday, to assess its military operational capability regarding war deterrence.

North Korean leader Kim Jong Un, who oversaw ​the missile launch, said: “It’s a ⁠very important strategy to maintain or expand the strong and reliable ​nuclear deterrent,” ⁠because of “the recent geopolitical crisis and various international circumstances,” according to KCNA.

The ‌missiles hit targets about ‌1,000 km (621 miles) away, over the sea east ‍of North Korea, KCNA said.

South Korean President visits China following Beijing's rising tensions with Japan over Taiwan

The South Korean military ‍said on Sunday (January 4) that North Korea fired ballistic missiles towards the sea to its east as South Korean President Lee Jae Myung started a ⁠state visit to China.