North Korea’s Kim Jong Un has met Vladimir Putin in Russia in a highly scrutinised visit which was expected to yield an arms deal.

After talks ended at the Vostochny space center, Mr Kim began his long journey home on his private armoured train, Russian state media reported.

Moscow has indicated it will help Pyongyang develop its satellites.

Both sides deny the US’ claim that the talks are aimed at buying weapons to support Russia’s war on Ukraine.

Besides advanced space technology, Mr Kim is also thought to have asked for food aid in return.

The meeting between the two sanctioned regimes – it included senior officials from both sides – took place at a time when their relations with the West are at an all-time low.

The high-profile visit saw Mr Kim, who travelled for two days to the Vostochny space center in Russia’s far east, warmly received by Mr Putin. Russian state media footage showed the two leaders grinning as they shook hands, before Mr Putin personally escorted Mr Kim around the space centre.

Asked if Russia would help North Korea build satellites, Mr Putin said “this is why we’ve come to Vostochny Cosmodrome”, Russian media reported.

Earlier this year North Korea twice tried, and failed, to launch a spy satellite. Pyongyang has vowed to develop one to boost its military surveillance capabilities.

Mr Putin also said they would “discuss all topics” when asked if he would talk to Mr Kim about military cooperation.

Later, Mr Kim appeared to express support for Mr Putin’s war in Ukraine.

“Russia has risen to a sacred fight to protect its sovereignty and security against the hegemonic forces,” Mr Kim told Mr Putin.

“We will always support the decisions of President Putin and the Russian leadership… and we will be together in the fight against imperialism.”

On Tuesday the US State Department spokesman Matthew Miller reiterated that any transfer of arms would violate UN Security Council resolutions and “a sign of the desperate state in which the Russian government finds itself” amid the Ukraine war.

He added that “we will not hesitate to take action to hold those accountable if necessary”.

The Kremlin had earlier said the interests of Russia and North Korea were important to them, “and not warnings from Washington”.

The meeting marked Mr Kim’s first trip abroad since 2019. The last time he travelled outside of North Korea was also to meet Mr Putin after the collapse of North Korea’s nuclear disarmament talks with then US President Donald Trump.

Many had expected him to head to Vladivostok where Mr Putin was attending an economic forum, but instead the train chugged northwards to Vostochny. On Wednesday morning, as Mr Kim neared his destination, North Korea fired two short-range missiles into the sea.

Mr Kim and Mr Putin’s meeting follows a Russian delegation’s visit to North Korea in July, where Mr Kim showed off Pyongyang’s missiles, including the Hwasong intercontinental ballistic missile, to defence minister Sergei Shoigu.

Moscow would be keen on North Korean arms due to their compatibility with Russian weapon systems, say experts.

They would be particularly keen for artillery shells and guns as artillery is “the god Russia worships” on the battlefront, said Valeriy Akimenko, an expert on Russia’s military with the Conflict Studies Research Centre.

Pyongyang would likely oblige in providing these as well as bullets and “even older types of missiles”, said Kim Dong-yup, a professor at the University of North Korean Studies.

Yang Uk, a research fellow at the Asian Institute for Policy Studies, said it is also possible that newer weapons such as short-range ballistic missiles could be supplied, such as the so-called “super-large” rocket KN-25.

Some analysts believe North Korea could have a large stockpile of arms as it has not fought a war since the Korean War ended in armistice in 1953, though others believe Pyongyang may be reluctant to hand over too much given their relative lack of resources.

But observers believe that North Korean weapons would only give a short-term boost to Moscow’s war effort. They say Moscow, with hugely depleted ammunition, is relying on older, more unreliable artillery shell stocks. North Korea’s arms could act “as a stop-gap measure” while Russia struggles to ramp up production, noted Mr Akimenko.

But given how fast Russia has been going through its supplies, the deal would not have much impact strategically. “It would kill more Ukrainians. But it will not kill Ukraine,” he added.

The impoverished North Korean regime, which has long struggled under sanctions, has been especially hit hard by border closures during Covid which it has only recently started relaxing.

Apart from food aid, Pyongyang may also ask for more advanced submarine and ballistic technology from Russia – though Mr Putin may draw a line at that, say some observers.

“Even a desperate war machine does not trade its military crown jewels for old, dumb munitions,” said Leif-Eric Easley, a professor at Ewha University in Seoul.

A deeper question posed by the meeting is whether heavy sanctions on Russia and North Korea are really working.

Rorry Daniels, managing director of the Asia Society Policy Institute (ASPI), said their meeting showed that international sanctions have created a “firewall” where the two countries “can transact business without fear of further punishment”.

“The more states under severe sanction are pushed together, the less the US can do to use sanctions as leverage to resolve the underlying conflicts.”

But the situation is also not without risk for Pyongyang, noted Park Won-gon, an associate professor in the Department of North Korean Studies at Ewha Womans University in Seoul.

If any evidence emerges indicating that North Korean weapons were used by Russia in Ukraine, “it may result in North Korea turning the entire Nato alliance against it, which could subsequently trigger additional sanctions.”

Additional reporting by Yuna Ku based in Seoul.