SEOUL, South Korea >> North Korea rolled out developmental ballistic missiles designed to be launched from submarines and other military hardware in a parade that punctuated leader Kim Jong Un’s defiant calls to expand his nuclear weapons program.

State media said Kim took center stage in Thursday night’s parade celebrating a major ruling party meeting where Kim vowed maximum efforts to bolster his nuclear and missile program that threatens Asian rivals and the American homeland to counter what he described as U.S. hostility.

During the eight-day Workers’ Party congress that ended Tuesday, Kim also revealed plans to salvage the nation’s economy amid U.S.-led sanctions over his nuclear ambitions, pandemic-related border closures and natural disasters that wiped out crops.

The economic setbacks have left Kim nothing to show for his ambitious diplomacy with President Donald Trump, which derailed over disagreements in exchanging sanctions relief and the North’s denuclearization steps, and pushed Kim to what is clearly the toughest moment of his nine-year rule.

Kim’s comments are likely intended to pressure the incoming U.S. government of Joe Biden, who has previously called the North Korean leader a “thug” and accused Trump of chasing spectacle rather than meaningful curbs on the North’s nuclear capabilities. Kim has not ruled out talks, but he said the fate of bilateral relations would depend on whether Washington abandons its hostile policy toward Pyongyang.

The Korean Central News Agency on Friday released photos of Kim wearing a black fur hat and leather trench coat, smiling widely and gesturing from a podium as thousands of troops and civilian spectators filled Kim Il Sung Square, named after his grandfather and North Korea’s founder.

The agency said spectators roared as troops rolled out the country’s most advanced strategic weapons, including submarine-launched ballistic missiles it described as the “world’s most powerful weapon.”

Photos released by state media showed trucks transporting what appeared to be a new submarine-launched ballistic missile that was larger than the ones the North previously tested.

The North also displayed a variety of solid-fuel weapons designed to be fired from mobile land launchers, which potentially expands the North’s capabilities to strike targets in South Korea and Japan, including U.S. military bases there.

The agency also said the parade featured other missiles capable of “thoroughly annihilating enemies in a pre-emptive way outside (our) territory.” But it wasn’t immediately clear whether the description was referring to intercontinental ballistic missiles.

As of Friday afternoon, the North’s state media did not release any images from the parade that included ICBMs.

During its previous military parade in October, the North unveiled what appeared to be its biggest-yet ICBM. The country’s previous long-range missiles demonstrated a potential ability to reach deep into the U.S. mainland during flight tests in 2017.

The North has been developing submarine-launched ballistic missile systems for years. Acquiring an operational system would alarm its rivals and neighbors because missiles fired from submerged vessels are harder to detect in advance.

Still, Kim Dong-yub, an analyst from Seoul’s Institute for Far Eastern Studies and a former military official who participated in inter-Korean military talks, said the North’s presumably new SLBM could possibly be an engineering mock-up that would require further development before it’s ready to be tested and deployed.

While Kim Jong Un during the congress vowed to develop nuclear-powered submarines capable of firing nuclear-armed ballistic missiles, it would take “considerable time” for the North overcome financial and technological difficulties to acquire such systems, the analyst said.

South Korea’s Joint Chiefs of Staff said in a statement it was studying the weapons displayed by the North but didn’t immediately release a detailed assessment.

It wasn’t immediately clear whether Kim Jong Un delivered a speech during the parade. North Korean state TV was expected to release footage of the parade later on Friday.

Nuclear-powered submarines were just one of many advanced military assets that were on Kim’s wish list during the congress, which also included longer-range ICBMs that could potentially target the U.S. mainland more reliably, new tactical nuclear weapons and warheads, spy satellites and hypersonic weapons.

It’s unclear whether the North is fully capable of acquiring such systems. While the country is believed to have accumulated at least dozens of nuclear weapons, outside estimates on the exact status of its nuclear and missiles programs vary widely.