Kim arrived onboard his armoured train at the Russian border on Tuesday morning, crossing the frontier at Russia’s Khasan city en route to the meeting where the Russian leader is expected to seek access to stockpiles of North Korean ammunition, which Moscow badly needs to feed its war in Ukraine.

The two leaders find themselves in changed circumstances since they last met in 2019, said Fyodor Tertitskiy, a historian of North Korea and leading researcher at Kookmin University’s Institute for Korean Studies in South Korea’s capital Seoul.

Both leaders have items to trade, advantages to gain and pressures at home that might encourage them to align their strategic interests more closely when they meet in Russia.

However, any agreement will be an “alliance of convenience” and one in which China – being the largest trading partner as well as Moscow and Pyongyang’s most powerful political patron – will tacitly have great influence in deciding the outcome, Tertitskiy said.

“The relationship between these two nations is based on lots of deception and rhetoric,” Tertitskiy told Al Jazeera, contextualising the current state of relations between Russia and North Korea.

While North Korea’s Western-facing media output may take a strong stance in support of Russia’s invasion of Ukraine, the media North Koreans consume has remained silent on the war, Tertitskiy said.

Many North Koreans may not even know that Russia has invaded its neighbour, he said.

‘Longer-term hazards for the world’

A fact not to be overlooked is that while the Soviet Union was an ally of North Korea, Russia is not, and Moscow’s approach to Pyongyang for many years has largely been to support China’s approach, Tertitskiy said. That has involved Moscow backing international sanctions on North Korea, which China supports, and refraining from supporting those Beijing does not back.

While Putin’s meeting with Kim in Vladivostok in 2019 resulted in little – and their imminent meeting this week might follow a formula of smiles, mutual condemnations of the West and no follow-ups – conditions internationally and domestically have changed for both since 2022, Tertitskiy said.

Putin’s army needs a supply of millions of artillery shells to continue with its city-flattening tactics in Ukraine.

Kim controls a vast domestic arms industry that produces munitions – artillery and rockets – compatible with Soviet-era weaponry still used by Russian forces.

Similar to Putin, Kim is in dire straits at home.

North Koreans are suffering serious food shortages, the economy needs commodities and fuel to keep going, and Kim wants hard currencies as well as access to the latest military technology to continue his plans for military modernisation, building more powerful intercontinental ballistic missiles (ICBMs), developing nuclear-armed attack submarines and launching a satellite.

Few could miss the symbolism should reports prove correct that the two leaders might hold their summit at Russia’s Vostochny Cosmodrome space centre in the Amur region.

That Putin and Kim can satisfy one another’s strategic interest is of concern beyond the war in Ukraine, said Daniel Salisbury, a visiting research fellow at King’s College London.

“North Korea desperately wants commodities such as food, oil, fertiliser and other goods,” Salisbury recently wrote in the academic news site, The Conversation.

On the other hand, Russia has “a vast military, nuclear and missile industrial complex, which…could provide Pyongyang much-needed technological fruits,” he said.

“If Moscow does move towards becoming a regular customer for embargoed North Korean arms, it will help Putin sustain his illegal war on Ukraine. But the potential technological payoff for Pyongyang could pose longer-term hazards for the world and must also be considered,” he said.

‘China is the only power which can really stop them’

Last week, United Nations National Security Adviser Jake Sullivan warned North Korea that it would “pay a price” if it provided weapons to Russia, without going into detail on his threat.

On Monday, the US State Department put more shape to those warnings, saying that any agreement between Kim and Putin on the trade in arms would be met with even more sanctions as a deal would violate United Nations Security Council resolutions.

When asked at a press briefing how many entities remained in North Korea that did not have US sanctions already imposed on them, State Department spokesman Matthew Miller said he was unable to answer.

While the question may have sounded a little sardonic, Miller’s answer was not.

North Korea has been subject to stringent UN sanctions for years due to its ongoing tests of ever more powerful ballistic missiles as well as efforts to develop nuclear weapons. Russia has also been subjected to rounds of sanctions since its invasion of Ukraine but has nevertheless continued on with its war.

Ankit Panda, an expert on North Korea’s weapons programme, lightly satirised US efforts to influence North Korea’s actions through such warnings on social media last week. “I suppose there are as-yet-untried adjectives with which we could pepper our sternly worded unilateral and joint press releases,” Panda wrote.

For Tertitskiy, there is little value in pressuring Moscow and even less attempting to apply pressure on North Korea. It would be smart for the US to turn its focus to Beijing if it does not want to see North Korean weapons used on Ukrainian battlefields.

The Kremlin views North Korea as firmly within China’s orbit and ”very rarely” would Moscow pursue a course of action that was not in lockstep with Beijing views.

While North Korea might like to diversify from China’s outsized influence over its economy, Russia cannot afford to ignore Beijing’s position when it comes to something as controversial as a potential trade in munitions for military technology between Moscow and Pyongyang.

And if a deal is done, Washington should know that, tacitly, it had the blessing of Beijing, Tertitskiy said.

“My advice to President Biden or to [Secretary of State] Antony Blinken or to anyone, I would say, ‘Send your ambassador to the Chinese’,” Tertitskiy said.

“China is the only power which can really stop them. Because, if they [China] say to Putin, ‘We are displeased at this, this is our sphere of influence, do not trade with these guys’, Putin will probably follow because he can’t afford angering the Chinese”.