SEOUL, South Korea (AP) — North Korean leader Kim Jong Un, accompanied by his teenage daughter, observed a live-fire test of multiple rocket launch systems, state media reported Sunday, a likely response to ongoing U.S.-South Korean military training that North Korea views as an invasion rehearsal.

The official Korean Central News Agency reported that Kim watched the strike drill involving twelve 600mm-calibre, ultraprecision rocket launchers off North Korea’s east coast on Saturday.

South Korea’s military said Saturday it detected about 10 ballistic missiles fired from North Korea’s capital region toward the eastern sea. South Korea’s national security council called the launches a provocation that violated U.N. Security Council resolutions that bans any ballistic activities by North Korea.

KCNA cited Kim as saying that the drill would expose enemies within the 420-kilometer (260-mile) striking range, to “uneasiness” and give them “a deep understanding of the destructive power of tactical nuclear weapon,” KCNA said. He apparently referred to South Korea and U.S. troops stationed in South Korea.

“If this weapon is used, the opponent’s military infrastructure within its striking range can never survive,” Kim said, according to KCNA.

KCNA photos showed Kim and his daughter, reportedly named Kim Ju Ae and aged about 13, walking near huge olive-green launch trucks and looking at weapons being launched from them. The girl has been accompanying her father at numerous high-profile events like missile tests and military parades since late 2022, stoking outside speculation that she’s being groomed as his heir.

Experts say North Korea’s large-sized rocket launchers blur the boundaries between artillery systems and ballistic missiles because they can create their own thrust and are guided during delivery. North Korea has said some of these systems are capable of delivering nuclear warheads.

The springtime U.S.-South Korean Freedom Shield training, a computer-simulated command post exercise, is to run through March 19. North Korea often reacts to the exercise with its own weapons tests and fiery rhetoric.