A picture released by North Korea’s Korean Central News Agency in April shows test-firing from a new warship.

SEOUL—North Korean leader Kim Jong Un’s dream of modernizing his country’s outdated naval fleet suffered a major setback after a much-touted warship crashed into the water after a botched exit from the dock.

Kim, who witnessed the mishap unfold at a Wednesday launch event, lambasted officials for their “absolute carelessness, irresponsibility and unscientific empiricism” in causing the “serious accident,” North Korea’s state media reported. The 41-year-old dictator equated the gaffe to a criminal act.

The unnamed 5,000-ton destroyer had been docked at a shipyard in Chongjin, a northeastern port city. As it was pushed sideways toward the water, the ship didn’t move in parallel. Its hull got crushed and its bow got stranded on the shipway, state media said.

Citing satellite imagery of the shipyard, South Korea’s military said the destroyer lay on its side in the water. North Korean state media didn’t publish images from the launch event or mention any injuries.

The warship represents one of Kim’s crown jewels in his push to upgrade North Korea’s naval fleet. Much of the country’s ships are from the Soviet era—and pale in comparison to the nuclear-powered submarines, warships and vessels possessed by the U.S. and South Korea.

Nuclear-armed North Korea has a growing arsenal of weaponry. But nearly all of it is land-based, and therefore more easily detectable. Advancing the Kim regime’s naval capabilities could expand the potential theater of combat and offer more unpredictability to its firepower.

Atop a country with serious food shortages, a down economy and widespread human-rights abuse, Kim has leaned heavily on military breakthroughs to boost morale and demonstrate the nation’s strength. Officials responsible for the warship blunder were censured for the fault. Kim vowed a turnaround by next month.

The accident, Kim was quoted as saying, “brought the dignity and self-respect of our state to a collapse.”

A satellite image taken before the failed launch shows the warship at the harbor in Chongjin, North Korea.

In recent months, Kim had showered extra attention on his country’s naval operations, visiting shipyards and touting breakthroughs. He oversaw a successful rollout in late April of another warship from the “Choe Hyon” class, named after a general who served under Kim’s grandfather and country founder Kim Il Sung.

Desiring for the North to become a maritime power, Kim Jong Un, in a lengthy speech, linked naval advances to his nation’s sovereignty, since the country has seas off its eastern and western coasts. A fleet of elite warships, he declared, guarantees peace and development.

Standing in front of the Choe Hyon-class vessel, Kim remarked: “I cannot suppress my emotions.”

Days later, Kim observed test-fires from the warship, including what state media said featured a supersonic cruise missile, an antiaircraft missile and a 127-mm ship-based gun.

The Choe Hyon-class warship features a Russian air-defense system and other design similarities with Russian weapons systems, according to South Korean lawmakers and weapons experts. Pyongyang and Moscow have boosted their military ties in recent years, with the collaboration including North Korea’s troop deployment to Russia, munitions shipments and weapons-development assistance.

Kim also visited a shipyard working on the country’s nuclear-powered submarine, North Korean state media reported in March, without providing a specific date. Such a submarine ranks among the North Korean leader’s top weapons priorities, alongside spy satellites and solid-fuel intercontinental ballistic missiles.