SEOUL, South Korea — North Korean leader Kim Jong Un has observed the test-firing of strategic cruise missiles from a navy ship, state media reported Monday, as the U.S. and South Korean militaries kicked off major annual drills that the North views as an invasion rehearsal.

The North’s report on missile tests came three days after the leaders of the U.S., South Korea and Japan agreed to expand their security and economic ties at a summit in the United States.

During an inspection visit of a navy flotilla on the eastern coast, Kim boarded a patrol boat to review its weapons and preparations for combat. He later watched its seamen conducting a drill of launching “strategic” cruise missiles, the official Korean Central News Agency said.

KCNA didn’t say when the missile launches happened, and a state media photo showed Kim watching the launch of a missile from another place, not on the patrol boat. KCNA’s use of the word “strategic” in reference to the tested weapons implied they were developed to carry nuclear warheads.

ADVERTISEMENT Advertisement

Kim said he would bolster efforts to build powerful warships and modernize shipboard and underwater weapons systems for the North’s navy. He called for the country’s sailors to build “overwhelming ideological and spiritual strength,” saying that is more important than numerical or technical superiority of weapons, according to KCNA.

North Korea was widely expected to resume weapons tests in reaction to the summer U.S.-South Korean military training that began Monday for an 11-day run.

The “Ulchi Freedom Shield” training is a computer-simulated command post exercise. The U.S. and South Korean militaries said they also plan conduct large-scale field exercises as well.

North Korea has slammed major U.S.-South Korean drills as practice for an invasion and has responded to them with missile tests. U.S. and South Korean officials maintain the exercises are defensive in nature and they have no intention of attacking the North.