Military top brass, political elites and ordinary party members will crowd Pyongyang for the twice-a-decade gathering, with supreme leader Kim Jong Un taking centre stage.

Here's what to watch for during the ninth congress of North Korea's ruling Workers' Party.

- Military showcase -

North Korea is yet to set a firm date for the start of the congress, aside from confirming the days-long spectacle will start sometime in "late February".

Observers have been scouring satellite imagery for any signs of the vast military parades that have marked previous gatherings.

Any parade will be closely watched for signs of a shift in North Korea's military bearing.

Pyongyang has used previous processions to show off its newest and most potent weapons, a rare source of insight into the strength of its armed forces.

- Nuclear ambitions -

Kim is widely expected to unveil the next stage in North Korea's heavily sanctioned nuclear weapons programme.

Over eight years since its last nuclear test triggered an earthquake below Mount Mantap, North Korea has been looking for ways to harness this power in smaller, more practical warheads.

Some analysts say Kim could announce that North Korea has equipped its military with long-range, nuclear-capable missiles.

"He is likely to declare the deployment of tactical and strategic nuclear assets to actual military units and tout military readiness with such mobilisations," said Lee Ho-ryung of the Korea Institute for Defense Analyses.

Such a declaration would be a blow to all those who still harbour hopes of convincing North Korea to give up its nuclear arsenal.

- Heir apparent -

Particular attention will be paid to the role of Kim's teenage daughter Ju Ae.

She has accompanied her father at missile launches and other important outings, fuelling speculation she has effectively been chosen as his heir apparent.

"She is likely to appear at the congress to bolster the narrative that she is soon to take an important political role in the future," said Lim Eul?chul, a professor at the Institute for Far Eastern Studies at Kyungnam University.

- Admitting failure -

Kim surprised observers at the last Workers' Party conference in 2021 when he made a rare admission of failure.

Addressing thousands of delegates packed into a cavernous hall, Kim admitted mistakes in plans for economic development in "almost all areas".

With its moribund state-managed economy still struggling under crippling sanctions, Kim is not expected to be so forthright this time around.

"The upcoming congress is likely to be a forum where regional developments and stronger defence capabilities will be touted, making it a 'victor's showcase'," said Hong Min, an analyst at the Korea Institute for National Unification.

- Friends or foes -

Pyongyang amended its constitution in 2024 to define South Korea as a "hostile state" for the first time.

South Korean President Lee Jae Myung has sought to mend ties with North Korea since taking office last year.

Kim has largely ignored his overtures.

At the previous congress five years ago, Kim declared that the United States was his nation's "biggest enemy".

There is keen interest in whether he might soften this stance, or double down.