North Korea test-fires hypersonic missiles in Sunday's drill

North Korea test-fired hypersonic missiles on Sunday, just hours before South Korean President Lee Jae Myung was due to leave for a summit in China.

Seoul said several ballistic missile launches were detected from the Pyongyang region at about 7:50 a.m. local time, accusing the North of carrying out provocations.

North Korea's state media confirmed that the missiles struck targets 1,000 kilometres away over the sea east of the country in a bid to assess military operational capability.

The DPRK's leader Kim Jong Un, who observed the missile launch, said that it's a pivotal strategy to maintain or expand the nuclear deterrent due to the recent geopolitical crisis and various international circumstances.

North Korea has previously conducted multiple tests to acquire a functioning hypersonic weapon, which is expected to allow it to penetrate the U.S. and South Korea's missile defence shields.

Pyongyang is set to hold a landmark congress of the ruling Workers' Party in a few weeks, the first in five years.