North Korea has revealed a nuclear-powered submarine under construction for the first time, which could be a serious security threat to South Korea and the US. On Saturday, state media shared photos of what it described as a nuclear-powered strategic guided missile submarine. The report also mentioned that leader Kim Jong Un visited major shipyards where these warships are being built.

North Korea's KCNA news agency didn't share specific details about the submarine but mentioned that leader Kim Jong-un was briefed on its construction. According to Moon Keun-sik, a South Korean submarine expert from Hanyang University in Seoul, the vessel appears to be between 6,000 and 7,000 tons and can carry around 10 missiles. He also noted that the term "strategic guided missiles" suggests the submarine is designed to carry nuclear-capable weapons. “It would be absolutely threatening to us and the US,” Moon said.

In 2021, during a major political meeting, Kim Jong-un announced plans to develop advanced weapons to counter what he called increasing military threats from the U.S. and its allies. His list included a nuclear-powered submarine, solid-fuel intercontinental ballistic missiles, hypersonic weapons, spy satellites, and multi-warhead missiles. Since then, North Korea has been testing these weapons to make them a reality.

Having the ability to launch missiles from underwater is a serious concern because it makes detection much harder for its enemies. However, many wonder how North Korea, a country struggling with sanctions and economic difficulties, is able to access the resources and technology needed to build a nuclear-powered submarine. Moon, a submarine expert, suggested that North Korea might have received Russian help in building a nuclear-powered submarine reactor. In exchange, North Korea may have supplied Russia with conventional weapons and troops for its war against Ukraine. He also mentioned that North Korea could launch the submarine within a year or two to test its capabilities before officially deploying it. North Korea has a large fleet of 70-90 submarines, but most of them are old and run on diesel. These submarines can only launch torpedoes and mines, not missiles.

North Korea claimed to have launched its first tactical nuclear assault submarine in 2023, but international analysts questioned the North's assertion and conjectured that it was probably a diesel-powered submarine that had been leaked in 2019. According to Moon, there is no proof that it has been deployed. Since 2016, North Korea has tested several underwater-launched ballistic missiles, but all of the launches have come from the same 2,000-ton, single-launch tube submarine. Several experts refer to it as a test platform instead than an active-duty submarine. North Korea has been intensifying its strong warnings against the US and South Korea as they prepare for their annual military drills, which begin on Monday. 

During his visits to the shipyards, Kim Jong Un stated that North Korea is working on upgrading both its surface and underwater warships at the same time. He emphasised the importance of building powerful warships that can counter the naval strategies of its adversaries, according to a report by KCNA on Saturday.