Kim Jong Un oversaw a huge public procession to celebrate the birthday of North Korea's founding leader, state media images showed Saturday, but the anniversary passed without an anticipated show of military strength.

Known as the Day of the Sun in the nuclear-armed country, the April 15 birthday of the late Kim Il Sung -- grandfather of current leader Kim Jong Un -- is one of the most important dates in Pyongyang's political calendar.

Analysts and South Korean and US officials had widely predicted a military parade or even a nuclear test, but the celebrations Friday involved a civilian parade, synchronised dancing and fireworks.

Photographs released by the state-run Korean Central News Agency showed thousands of colourfully dressed people marching through the capital's Kim Il Sung Square as Kim Jong Un looked on from a balcony.

"Columns of workers, peasant dancers and others marched past the square," carrying banners and boards bearing socialist slogans, and a giant national flag, KCNA said.

Three generations of the Kim family have ruled the country since 1948.

Kim also visited the Kumsusan Palace of the Sun, where the bodies of Kim Il Sung and his son and successor Kim Jong Il lie in state.

Civilian, not military

There was a steady drumbeat of celebratory coverage in state media leading up to the day, including the opening of new apartment complexes, light festivals and floral tributes.

It was a calculated decision to highlight new apartments and citizens with smartphones taking pictures of flowers, said Leif-Eric Easley, associate professor of international studies at Ewha Womans University in Seoul.

"The Kim regime needs more sources of national pride and legitimacy than military parades," he said.

"So the public commemorations around its founder's birthday tried to portray an economy that is not only resilient but growing."

The anniversary celebrations came three weeks after North Korea staged its largest intercontinental ballistic missile test ever -- the first time Kim's most powerful weapon had been fired at full range since 2017.

That test was the culmination of a record-breaking blitz of sanctions-busting launches this year and signalled an end to a self-imposed moratorium on long-range and nuclear tests.

The absence of military activity on the holiday "does not represent a shift away from North Korea's military build-up", Easley added.

Satellite imagery has shown signs of new activity at a tunnel at the Punggye-ri nuclear testing site, which North Korea said was demolished in 2018 ahead of a summit between Kim and then-US president Donald Trump.

South Korean officials have said Pyongyang could still stage a military parade or carry out a weapons test on or around April 25, the anniversary of the founding of the Korean People's Army.

AFP