This transfer is part of a geopolitical strategy of greater confrontation with the West, in which both countries position themselves as allies against pressure from the United States and its Asian allies.
According to South Korean intelligence, Russia has reportedly supplied a nuclear reactor for North Korean submarines
This transfer is part of a geopolitical strategy of greater confrontation with the West, in which both countries position themselves as allies against pressure from the United States and its Asian allies.
The advantage of nuclear submarines over conventional ones lies in their virtually unlimited autonomy and their ability to operate for long periods without needing to surface, as they do not depend on atmospheric oxygen. Only a small group of countries, such as the United States, Russia, China, the United Kingdom, and France, currently possess this technology.
In March 2025, North Korea publicly showed that it is building a nuclear-powered strategic guided missile submarine, during an official visit by Kim Jong Un. Back then, the North Korean leader reaffirmed that the development of a maritime nuclear force is essential for national defense, especially in the face of what he considers hostile maneuvers by the United States and South Korea in the region.
During a meeting between Kim Jong Un and Russian President Vladimir Putin in Beijing, on September 3, Putin publicly praised North Korean soldiers for their support in Ukraine, highlighting the "special dimension of trust and alliance" between both nations.
If North Korea manages to put a nuclear submarine into operation in the coming months, this could trigger a regional response, including the possibility that South Korea will accelerate the development of its own nuclear submarine.
According to intelligence information obtained by South Korea, Russia has reportedly provided North Korea with a nuclear reactor, along with other key components, to boost the development of its nuclear submarine fleet.
The revelation, reported by the South Korean newspaper Korea JoongAng Daily and based on multiple government sources, has caused international concern, as it points to a significant advance in North Korea's naval military capability.
The information suggests that Russia delivered between two and three nuclear modules for submarines during the first half of the year, including a reactor, a turbine, and a cooling system.
These components would not be newly manufactured, but would have been repurposed from dismantled Russian submarines. If confirmed, this would mark the first time Russia has transferred nuclear submarine propulsion technology to North Korea.
South Korea has already shared this intelligence with its allies, including the United States, and is verifying the credibility of the data. The South Korean Defense Intelligence Agency stated that it is closely monitoring the situation.
This development comes in the context of an increasingly close military alliance between Moscow and Pyongyang. Last year, both countries signed a strategic partnership pact, which includes mutual military assistance. Under this agreement, North Korea has sent troops and munitions to support Russia in its war against Ukraine, in exchange for more advanced Russian military equipment.
One of the cited South Korean officials indicated that Russia was initially reluctant to transfer such sensitive technology, including nuclear submarines and advanced fighter jets, but eventually agreed after North Korea's persistent requests since 2024.