In unprecedented scenes, Xi shook hands with both leaders and chatted with the pair as they walked down a red carpet by Tiananmen Square, with Putin to Xi's right and Kim to his left.

The event, ostensibly to mark 80 years since the end of World War II, was a chance for Xi to showcase China's military prowess and bring together friendly leaders to send a message to the rest of the world.

Kicking off the parade, Xi warned the world was still "faced with a choice of peace or war", but said China was "unstoppable".

China's enormous new intercontinental DF-5C ballistic missile, with a range of 20,000 kilometres (12,425 miles), counted prominently among the hardware on display.

The heavily choreographed event drew an acidic response from President Donald Trump, who accused the three leaders of plotting against the United States.

"Give my warmest regards to Vladimir Putin, and Kim Jong Un, as you conspire against The United States of America," he wrote on Truth Social.

The European Union's foreign policy chief denounced the presence of the Russian and North Korean leaders alongside Xi as "a direct challenge to the international system built on rules".

"A new global order is in the making," Kaja Kallas told journalists in Brussels.

Putin vowed to carry on the war in Ukraine if a peace deal could not be reached, with Trump's diplomatic initiatives appearing to have stalled.

"Let's see how the situation develops. If not, then we will have to resolve all our tasks militarily," Putin told reporters in Beijing.

- Military hardware on show -

Xi inspected the massed troops and weaponry from an open-topped limousine on Beijing's vast Chang'an Avenue during the 90-minute parade, before turning back to join his guests in a seating area above a portrait of Mao Zedong on Tiananmen, the entrance gate of the historic Forbidden City.

China's huge collection of military vehicles and heavy weapons rolled past the dignitaries, while images of thousands of servicemen and women in immaculate uniforms marching in tight ranks and soldiers jumping in and out of vehicles were shown in a slick state media broadcast.

New underwater drones and supersonic missiles counted among the gear on display, as well as the ICBMs.

Beijing residents went out into the streets to glimpse a flypast involving scores of warplanes and helicopters, some making an "80" formation.

Millions of Chinese people were killed during a prolonged war with imperial Japan in the 1930s and 40s, which became part of a global conflict following Tokyo's 1941 attack on Pearl Harbor.

- Whirlwind week -

All eyes were on how Xi, Putin and the travel-shy Kim interacted with each other, but the state media broadcast only rare snatches of the three together. Foreign journalists were kept at a distance and told not to film or photograph the leaders.

The event was the climax of a whirlwind week for Xi, who hosted a slew of Eurasian leaders for a summit aimed at putting China front and centre of regional relations.

During the summit, Xi slammed "bullying behaviour" from certain countries -- a veiled reference to the United States.

Many guests from the Shanghai Cooperation Organisation summit in Tianjin joined Xi for the Beijing parade, although no major Western dignitaries were among the two dozen world leaders who attended.

- Political influence -

Security around Beijing was tightened, with road closures, military personnel stationed on bridges and street corners, and miles of white barriers lining the capital's wide boulevards.

China has touted the parade as a show of unity, and Kim's attendance is the first time he has been seen with Xi and Putin at the same event. It is only his second reported trip abroad in six years.

Kim was accompanied by his daughter Kim Ju Ae and his sister Kim Yo Jong, who was photographed by AFP at a gala lunch on Wednesday.

Putin and Kim held talks after Wednesday's parade, during which the Russian president thanked Kim for deploying North Korean soldiers to aid Russia in its conflict with Ukraine.

Lam Peng Er, principal research fellow from the East Asian Institute at the National University of Singapore, said Kim's visit "demonstrates to the North Koreans and the world that he has powerful Russian and Chinese friends who treat him with respect".

"China also shows that it has convening power and political influence to bring Putin and Kim Jong Un together," he told AFP.