North Korean leader Kim Jong Un attending a military parade in the centre of Beijing, alongside Russian president Vladimir Putin and China's leader Xi Jinping, is quite the photo-op.

It's also a key diplomatic win for Xi.

The Chinese leader has been trying hard to project Beijing's power on the international stage - not just as the world's second-largest economy, but also as a diplomatic heavyweight.

He has emphasised China's role as a stable trading partner while Trump's tariffs upended economic relationships.

Now, while a deal with Putin to end the war in Ukraine continues to elude the US President, Xi is getting ready to host him in Beijing.

Kim's attendance, a surprise announcement, is no less significant. Trump said earlier this week, in a meeting with the South Korean president, that he wanted to meet Kim Jong Un again.

His last shot at diplomacy with the reclusive dictator ended with no breakthroughs - despite two summits that captivated the world. Trump is suggesting he wants to try again.

Meanwhile, the Chinese leader is signalling that he may hold the geopolitical cards in this game, and that his influence – though limited – on both Kim and Putin may prove crucial in any deal.

The parade on 3 September will see a display of China's military might to mark 80 years since Japan surrendered in World War Two, bringing an end to its occupation of parts of China.

But now Xi has also turned it into a display of something more - and the timing is key. The White House has suggested that President Trump could be in the region at the end of October and is open to meeting Xi.

There is plenty on the table for them to discuss, from a long-awaited tariffs deal and the sale of TikTok in the US, to Beijing's ability to persuade Putin to agree to a ceasefire or more in Ukraine.

Now, having met both Kim and Putin, the Chinese leader would be able to sit down with Trump without feeling like he has been left out of the loop – and given his close relationship with both leaders, he may even have information his US counterpart does not.

Russia and North Korea are pariahs in the eyes of the western world. Kim for much longer than Putin because of his weapons programme, but his support for Moscow's invasion of Ukraine has renewed the condemnation.

So the invitation to Beijing is a big step for him - the last time a North Korean leader attended a military parade in China was in 1959.

There has been little public contact between Xi and Kim since 2019, when they met to mark the 70th anniversary of China-North Korean ties. Beijing was also Kim Jong Un's first stop in 2018 before his summits with President Trump to curb Pyongyang's nuclear programme.

More recently, Xi even appeared to be on the sidelines of a deepening Moscow-Pyongyang alliance, one that perhaps Beijing wanted no part of.

China has tried to stay publicly neutral on the war in Ukraine, while urging a peaceful solution. But the US and its allies have accused Beijing of supporting Moscow's efforts by supplying components Russia can use in its war effort.

Some analysts wondered if China's relationship with North Korea had soured as Kim grew closer to Putin. But Kim's visit to Beijing next week suggests otherwise.

It's not a relationship the North Korean leader can easily give up - his economy depends heavily on China, which provides almost 90% of food imports. And being on that stage with not just Putin and Xi, but other leaders, from Indonesia, Iran etc, also offers Kim legitimacy.

For Xi, this is diplomatic leverage with Washington ahead of a possible summit with Trump.

The two countries have continued talks to try and strike a deal and avert ruinous tariffs and a trade war. Another 90-day pause is under way but the clock is ticking, so Xi will want the strongest hand possible as negotiations go on.

He has much to offer: China has helped Trump in the past when he tried to meet Kim Jong Un. Could Xi do that again?

More important perhaps is what role China could play in ending the war in Ukraine.

The most striking question of all: could there be a meeting between Xi, Putin, Kim and Donald Trump?(BBC)