North Korea heralded the successful development of a new “high-thrust engine” during a visit to the country’s rocket test site by leader Kim Jong Un, the reclusive nation’s state media said Sunday.

Kim observed the test of the indigenously built high-powered engine at the North’s Sohae satellite facility in Dongchang-ri on Saturday, according to the Korean Central News Agency.

The facility is near the site where the isolated country launched four extended-range Scud missiles earlier this month as part of a practice exercise aimed at striking U.S. military bases in Japan.

Kim said that the “development and completion of the engine would help consolidate the scientific and technological foundation to match the world-level satellite delivery capability,” the report said — an indication that the test was likely that of a long-range rocket engine.

KCNA said the purpose of the test was to confirm the reliability of the engine’s features, including its thrust power in the combustion chamber and the movements of various valves.

Rocket engines can be easily repurposed for use in missiles.

Pyongyang is banned by the U.N. from conducting long-range missile tests, but it claims its satellite program is for peaceful use, a claim many in the U.S. and elsewhere have called dubious.

KCNA quoted Kim as saying that the successful test was a “great event of historic significance” that marked the “new birth” of the country’s rocket industry as the North seeks to erase its dependence on other countries’ technology.

“The whole world will soon witness what eventful significance the great victory won today carries,” Kim said, according to KCNA.

In September, the North announced the successful ground test of a new type of “high-power engine,” ostensibly for launching satellites. State media said the engine could deliver 80 tons of thrust, making it likely the most powerful the country had ever seen.

David Schmerler, a researcher at the Center for Nonproliferation Studies at the Middlebury Institute of International Studies in California, said Saturday’s test was different from the engine tested last September.

“This appears to be a single-nozzle engine with four vernier thrusters,” Schmerler said, referring to thrusters used to maneuver and stabilize the spacecraft. “We haven’t seen this configuration before in North Korea.”

Schmerler said it could be a new second-stage engine for the North’s next satellite launch vehicle.

“However, it may also have a dual use in their ballistic missile program,” he added.

The test comes as the North gears up for the 85th anniversary of the founding of the Korean People’s Army.

Earlier this month, Pyongyang issued an unusually overt threat to the Washington and Tokyo, firing off a simultaneous barrage of four missiles as part of exercises that it said were training for strikes on U.S. military bases in Japan.

Prime Minister Shinzo Abe has characterized the exercise as exemplifying “a new level of threat” from Pyongyang.

Missile experts said the hypothetical target of that drill appeared to be U.S. Marine Corps Air Station Iwakuni in Yamaguchi Prefecture.

Observers said the undisguised threat to U.S. bases in Japan was rare, even for Pyongyang, which routinely serves up colorful invectives.

There has been growing speculation that the North will conduct an intercontinental ballistic missile (ICBM) test after Kim used a New Year’s Day address to claim that Pyongyang was in the final stages of developing a long-range missile capable of hitting New York and Washington.

The international community has been piling pressure on the North after it conducted two nuclear tests and launched more than 20 missiles last year — almost twice as many as it did under the rule of Kim Jong Un’s father, Kim Jong Il.

The U.S. is currently undergoing a review of its North Korea policy, with President Donald Trump dispatching Secretary of State Rex Tillerson to the region for meetings in Tokyo, Seoul and Beijing, as Washington grapples with the seemingly intractable issue.

Tillerson met with Chinese President Xi Jinping on Sunday, with the expectation going in that North Korea’s nuclear program would top the agenda.