SEOUL, South Korea (AP) — North Korea said Tuesday it had test-fired a new tactical ballistic missile capable of carrying a huge warhead, as the country is pushing to modernize its weapons arsenal to cope with what it calls U.S.-led threats.

The North’s official Korean Central News Agency called the weapon Hwasongpho-11Da-4.5 which can carry 4.5 ton-class “super-large warhead.”

It said the test-fire on Monday was meant to verify flight stability and hit accuracy at the maximum range of 500 kilometers (310 miles) and the minimum range of 90 kilometers (55 miles).

South Korea’s military earlier said that North Korea launched two ballistic missiles from one of its southwestern towns in a northeastern direction on Monday and that the first missile flew 600 kilometers (370 miles) and the second missile 120 kilometers (75 miles). The second missile's flight distance was too short to reach the waters off the North's east coast, a typical landing site for North Korean test missiles.

South Korea’s Joint Chiefs of Staff said the second North Korean missile possibly travelled abnormally during the initial stage of its flight. It said if the missile exploded, its debris would likely have scattered on the ground though no damages was immediately reported.

The KCNA dispatch didn’t say from where it launched the new missile and where it landed. But the fact that it tested both the missile’s maximum and minimum ranges suggested North Korea performed two launches.

KCNA, citing North Korea’s Missile Administration, reported that North Korea will test-fire the missile again later in July to verify the performances of its simulated warhead at the medium range of 250 kilometers (155 miles).

Since 2022, North Korea has sharply accelerated weapons testing activities to enlarge its arsenal of nuclear-capable weapons designed to strike key sites in the mainland U.S., South Korea and Japan. The ranges of the newly tested missile suggest it targets South Korea. Experts say North Korea would ultimately want to use an expanded nuclear arsenal to increase its leverage in future diplomacy with the U.S.

Monday's missile's test were the North Korea's first weapons firing in five days. Last Wednesday, North Korea launched what it called a multiwarhead missile in the first known test of a developmental weapon aimed at penetrating its rivals' missile defenses. North Korea said the launch was successful, but South Korea dismissed the North’s claim as deception to cover up a failed launch.

The latest launches came a day after North Korea vowed “offensive and overwhelming” responses to a new U.S. military drill with South Korea and Japan.