Russia's defence minister was photographed this week viewing banned North Korean ballistic missiles with leader Kim Jong Un at a military expo in Pyongyang, signalling deeper ties between the two countries as they face off with the United States.
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:
Political backing
Communist North Korea was formed in the early days of the Cold War with the backing of the Soviet Union. North Korea later battled the South and its US and United Nations allies to a stalemate in the 1950-1953 Korean War with extensive aid from China and the Soviet Union.
North Korea was heavily reliant on Soviet aid for decades, and when the Soviet Union collapsed in the 1990s, it contributed to a deadly famine in the North.
Pyongyang's leaders have tended to try to use Beijing and Moscow to balance each other. North Korean leader Kim Jong Un initially had a relatively cool relationship with Russia and China, which both joined the United States in imposing strict sanctions on North Korea over its nuclear tests.
After his country's last nuclear test in 2017, Kim took steps to repair ties.
He 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".
In a message for Russia's National Day in June, Kim vowed to "hold hands" with Putin and bolster strategic cooperation.
Russia has joined China in opposing new sanctions on North Korea, blocking a US-led push and publicly splitting the U.N. 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.
The United States has accused North Korea of providing arms to Russia for the war effort, including a "significant" number of artillery shells, as well as a shipment of infantry rockets and missiles to the private Russian military company, the Wagner Group.
Both Russia and North Korea have denied those claims, but this week promised to deepen defence cooperation.
"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 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.
Economic ties
Last year, Russia and North Korea 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.
Shortly after that Russia also resumed oil exports to North Korea, United Nations data shows, the first such shipments reported since 2020.
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 labourers, 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.