Planning for the spectacle, which could begin as early as Thursday, has been shrouded in secrecy, with South Korea's military saying the North may stage the parade at night.

It comes as North Korea's leader Kim Jong Un has been emboldened by the war in Ukraine, securing critical support from Russia after sending thousands of North Korean troops to fight alongside Moscow's forces.

Last month, Kim appeared alongside Chinese President Xi Jinping and Russian leader Vladimir Putin at an elaborate military parade in Beijing.

Chinese Premier Li Qiang will lead the Chinese delegation to this week's 80th anniversary celebrations, while the deputy head of Russia's Security Council, Dmitry Medvedev -- a key Putin ally -- will also be in Pyongyang.

The grand event will be a "public spectacle that materialises the strategic consolidation of the China-North Korea-Russia axis," Seong-Hyon Lee, a visiting scholar at the Harvard University Asia Center, told AFP.

- 'Not a client state' -

"More strategically, Kim is demonstrating his worth as a partner. By displaying advanced weaponry and a powerful military, he is telling Beijing and Moscow, 'I am not a client state; I am a valuable and capable ally,'" Lee said.

Analysts expect the parade to showcase a new solid-fuel intercontinental ballistic missile (ICBM) that could put the US mainland within Pyongyang's reach, as well as new drones and hypersonic weapons aimed at threatening US forces.

"The Ukrainian war reportedly showed Pyongyang the importance of the 'drone revolution' in warfare and they are doing their best to catch up now, assumedly with Russian help," said Vladimir Tikhonov, professor of Korea studies at the University of Oslo.

Joseph Dempsey of the International Institute for Strategic Studies said recently released images from North Korea's defence exhibition provide a "good teaser" for the upcoming parade.

One new system seen in the images appears to resemble Russia's Pantsir air-defence system mounted on a North Korean tracked vehicle -- which is "potentially very noteworthy given the deepening military ties with Moscow," Dempsey told AFP.

- A 'message' to Trump -

The celebrations in Pyongyang come after Seoul said a meeting between North Korea and the United States "cannot be ruled out" on the sidelines of this year's APEC summit in South Korea.

US President Donald Trump met Kim three times during his first term and once famously said the pair had fallen "in love", but he ultimately failed to secure a lasting agreement on North Korea's nuclear programme.

Ties between Pyongyang and Washington have been in the deep freeze since the last summit between Kim and Trump collapsed in 2019 over disagreements on sanctions relief and Pyongyang's nuclear concessions.

Since then, North Korea has repeatedly declared itself an "irreversible" nuclear state.

The US President said in August he hoped to meet Kim again, possibly this year, while Pyongyang has said Kim had "fond memories" of Trump and was open to future talks if Washington dropped its demand that the North give up its nuclear weapons.

Kim said this week that the country's alliance with Russia "will be invariably carried forward in the future".

The upcoming parade will be Pyongyang's message to Trump that "the old formula for dealing with North Korea is defunct", said Harvard's Lee.

By displaying his most powerful weapons "alongside top officials from China, Russia", Lee said, "Kim is declaring: 'Your strategy of outsourcing the North Korea problem to Beijing is over.'"