When North Korean leader Kim Jong-un visited Russian President Vladimir V. Putin four years ago in his only previous meeting, it was largely for diplomatic reasons.
But this week he will meet Mr. Putin with the ability to deliver something the Kremlin desperately needs: ammunition that could help Russian forces fighting in Ukraine.
In return, Russia could give North Korea some of what it needs — food, oil or hard currency — and transform a relationship long limited to modest trade and public displays of cooperation into something more substantial.
Such a transaction, with mutual benefits for both sides, would represent “the real end of an era of the relationship that began in 1990,” said Fyodor Tertitskiy, a senior researcher at Kookmin University in Seoul.
Since then, Mr. Tertitskiy said relations between the two countries have been characterized by a lot of “talk and no real trade,” noting that a deal in which Russia provides something of value to North Korea in exchange for ammunition would mark a departure .
It was not clear when the meeting would take place, but a train similar to the one Mr. Kim prefers for his rare trips outside the country was photographed on Monday near the border between the two countries heading for Vladivostok, the eastern Russian port city, in Mr. Putin took part in an economic conference. It was also the location of their meeting in 2019.
Another meeting with Mr. Kim will be the latest example of Putin’s efforts to strengthen ties with leaders who are also hostile to the Western world, some of whom may help Russia in its war against Ukraine.
Mr Putin made a rare international trip to Iran last year to meet with Ayatollah Ali Khamenei, Iran’s supreme leader, and the country’s president, as Russia became increasingly isolated from the West because of the invasion.
In the months since, Iran has emerged as a major supplier of drones to Moscow, which Russian forces have used against Ukraine both on the battlefield and in attacks on civilian infrastructure.
Mr Putin has also appeared with the Kremlin’s closest ally, Belarusian President Aleksandr G. Lukashenko, who granted Russia access to his country’s territory in February last year to launch its invasion of Ukraine.
The Pentagon said this month that Russia had specifically asked North Korea for ammunition, noting that the request was the result of problems Moscow was having replenishing its battlefield stockpiles.
Russian Defense Minister Sergei K. Shoigu visited North Korea in July on a trip that U.S. officials said at the time was aimed at concluding an arms deal.
North Korea has one of the largest armies in the world, despite only having a population of about 26 million. The country operates on a war footing at all times, and artillery would be a crucial part of any renewed war with South Korea. Analysts believe North Korea has a surplus of ammunition because it has not fought a war since signing the armistice agreement with Korea in 1953.
Petr Akopov, a pro-war columnist for the Russian state news agency RIA Novosti, suggested in a recent article that Russia could “unofficially” transfer military technology to Pyongyang and welcome North Korean construction workers to Ukraine’s occupied territories in exchange for ammunition and certain types of material of rockets.
“All of this is hampered to some extent by UN Security Council sanctions, but there are always ways around them,” Mr. Akopov wrote.
Mr Akopov added: “The world is changing, and the countries that have challenged the Western world order will not be able to change it by playing by its rules.”