The United States said this week it has information indicating North Korea is covertly supplying Russia with a "significant" number of artillery shells, in what would be a further sign of deepening ties between the two pariah states, Reuters reports.
As Russia's isolation over its war in Ukraine has grown, it has seen increasing value in North Korea. For North Korea's part, relations with Russia haven't always been as warm as they were during the heady days of the Soviet Union, but now the country is reaping clear benefits from Moscow's need for friends.
Here's how North Korea-Russia relations began, and how they are becoming closer:
Kim met Russian President Vladimir Putin in 2019 for the first time in a summit in the Russian city of Vladivostok.
In October, Kim sent a birthday greeting to Putin, congratulating him for "crushing the challenges and threats of the United States".
Russia has joined China in opposing new sanctions on North Korea, vetoing a US-led push in May and publicly splitting the UN Security Council (UNSC) for the first time since it started punishing Pyongyang in 2006.
UKRAINE WAR SUPPORT
North Korea has reciprocated with public support for Moscow after Russia invaded Ukraine. It was one of the only countries to recognise the independence of breakaway Ukrainian regions, and it expressed support for Russia's proclaimed annexation of parts of Ukraine.
"Moscow's 'special military operation' in Ukraine has ushered in a new geopolitical reality in which the Kremlin and (North Korea) may become increasingly close, perhaps even to the point of resurrecting the quasi-alliance relationship that had existed during the Cold War," Artyom Lukin, a professor at Far Eastern Federal University in Vladivostok, wrote in a recent report for 38 North.
It is notable Pyongyang has begun using the new phrase "tactical and strategic collaboration" to describe its relationship with Russia, he added.
Both Russia and North Korea have denied claims by the United States that Russia has sought to buy millions of rounds of ammunition and other weapons from North Korea.
ECONOMIC TIES
Russia and North Korea recently restarted train travel for the first time since railway journeys were cut during the COVID pandemic with an unusually opulent cargo - 30 grey thoroughbred horses. Russia's RIA state news agency said medicines would follow in later cargos.
The vast majority of North Korea's trade goes through China, but Russia is a potentially important partner as well, particularly for providing oil, experts said. Moscow has denied breaking UN sanctions, but Russian tankers have been accused of helping evade caps on exporting oil to North Korea and sanctions monitors have reported labourers remain in Russia despite a ban.
Russian officials have openly discussed "working on political arrangements" to employ 20,000 to 50,000 North Korean labours, despite UN Security Council resolutions that ban such arrangements.
Russian officials and leaders in the breakaway regions in Ukraine have also discussed the possibility of having North Korean workers help rebuild those war-torn areas.