North Korea's Kim hails 'new-type weapon' days after missile launch sparks anger

North Korean leader Kim Jong-un oversaw the test of a "new-type weapon" system, touting it as evidence of the country's advancing military technology, state media reported on Tuesday.

The announcement came two days after South Korea and Japan said Pyongyang launched two short-range ballistic missiles into waters off its east coast, which the countries condemned as threats to regional peace and security.

North Korea has legally enshrined its status as a nuclear-armed state, with its leadership repeatedly declaring the country's atomic arsenal permanent and irreversible.

The nuclear-armed country's missile bureau "successfully tested a new type of weapon" in the presence of its leader Kim Jong-un on Sunday, Pyongyang's official Korean Central News Agency (KCNA) said.

Pyongyang did not specify what the weapon system entailed, but said Kim praised the launch as an "undoubtedly a striking demonstration of ultra-modern defence technology."

The North Korean leader warned that the advances would give adversaries "an incurable headache and a very cruel and unavoidable blow," KCNA said.

The Sunday launches came eight days after North Korea fired multiple short-range ballistic missiles towards the East Sea, also known as the Sea of Japan, as part of what it later described as a joint firepower drill.

That exercise involved long-range artillery and missiles, with the weapons "hitting the targets with 100 percent accuracy," state media reported.

In the Tuesday report from KCNA, Kim linked Sunday's test to the country's military preparedness, saying "to acquire such a technology is of weighty significance in the state's readiness for war and the future development of the armed forces."

Seoul condemned the launches as a violation of UN Security Council resolutions and urged Pyongyang to halt its ballistic missile activities.

Japan lodged a "stern protest" with North Korea over the launches, calling them as a threat to regional peace and security.

Last week, Pyongyang rejected a resolution adopted at the International Atomic Energy Agency demanding it halt its nuclear activities, saying its nuclear weapons status was "irreversibly and permanently fixed" by its laws.

North Korea's foreign ministry spokesperson said the IAEA resolution "has no effect on the DPRK's position as a nuclear weapons statem" using the acronym for North Korea's official name.

Kim Yo-jong, the powerful sister of North Korean leader, recently said the country's nuclear-armed status was "absolute" and called those hoping for its denuclearisation "idiots."