North Korea confirmed Tuesday that it tested a tactical ballistic missile a day earlier to verify a technological upgrade to a key component, saying the development could improve the performance and sophistication of its offensive weapons systems.
The country’s Missile Administration conducted the test Monday as part of regular research aimed at modernizing missile technology, state-run Korean Central News Agency, or KCNA, reported.
KCNA said the test was carried out “to confirm the success in the research for the technical upgrading of an important core element,” without providing further details about the component.
The Missile Administration described the upgrade as a “big success,” saying it could bring an important change in improving the performance and sophistication of offensive weapons systems.
South Korea’s Joint Chiefs of Staff said Monday that its military detected several ballistic missiles launched from the Pyongyang area toward the East Sea, also known as the Sea of Japan, at around 9:20 a.m.
Some of the missiles traveled more than 900 kilometers, or about 560 miles, according to the South Korean military.
“Our military has stepped up surveillance and vigilance against possible additional launches,” the Joint Chiefs of Staff said.
South Korea’s National Security Office convened an emergency security meeting following the launches to review the country’s military readiness.
Japan’s Defense Ministry separately confirmed the launch of at least one suspected ballistic missile.
The U.S. Pacific Command said North Korea launched two ballistic missiles and assessed that they did not pose an immediate threat to U.S. personnel, territory or allies.
The reason for the differing numbers of missiles reported by North Korea, South Korea, Japan and the U.S. was not immediately clear.
Seoul suggested the launches could have been a response to South Korea’s successful test of a hypersonic glide vehicle last week.
The missile activity came after weeks of heightened tensions following a landmine explosion in the South Korean-controlled section of the Demilitarized Zone, or DMZ, that injured three South Korean soldiers.
Both North and South Korea have since tested upgraded missile technology.
A joint investigation by South Korea and the U.N. concluded last week that North Korea had planted the landmines more than a year earlier.
Pyongyang has denied the accusation.
Kim Yo Jong, the sister of North Korean leader Kim Jong Un, criticized South Korean demands for an apology as “despicable” and separately rejected an offer of medical equipment from Seoul.