SEOUL: Nuclear-armed North Korea unveiled a new submarine-launched ballistic missile at a military parade in Pyongyang, state media showed Friday, in a calculated show of strength days before Joe Biden’s inauguration as US president.

The display came after the five-yearly congress of the ruling Workers’ Party, where leader Kim Jong Un decried the US as his country’s “foremost principal enemy”.

A grinning Kim oversaw the parade on Thursday evening, wearing a black leather coat and fur hat as he watched mounted cavalry, specialist infantry, artillery and tanks roll through Kim Il Sung Square.

The troops’ breath condensed in the cold winter air and none of the thousands of participants were seen wearing masks.

Aircraft flew overhead forming the party symbol.

“The world’s most powerful weapon, submarine-launch ballistic missile, entered the square one after another, powerfully demonstrating the might of the revolutionary armed forces,” the official KCNA news agency said.

Four of the SLBMs with black-and-white cones were driven past, footage on state television showed, and Park Won-gon of Handong Global University in the South described them as “the North’s ultimate nuclear weapon”.

The North has shown off earlier, smaller SLBMs before, and broadcast footage of a test launch, but it was not clear whether they were fired from a submarine or an underwater platform.

A working SLBM on a nuclear-powered submarine would be a strategic game changer, enabling Pyongyang to launch a surprise attack from close to the United States or carry out a strike even if its land-based forces had been destroyed.