North Korea first presented a nuclear -powered submarine under construction, a weapon system that can be a major threat to the safety of South Korea and the United States.

State media posted photos on Saturday showing what they call “strategic nuclear -powered underwater rockets”, conveying the visits of leader Kim Jong Un to large yards where warships are being built.

The Korean Central News Agency (KCNA) did not provide details of the submarine, but said Kim was informed of its construction.

The naval vessel appears to be a class of 6,000 or 7,000 tonnes and can carry about 10 missiles, said Moon Kune-Sik, a submarine specialist and a professor at Hangiyang University in Seoul. He added that the use of the term “strategic guided missiles” means that the submarine will carry nuclear weapons.

“It will be an absolute threat to us and the US,” Moon noted.

The nuclear -powered submarine was among the sophisticated weapons systems that Kim had pledged to build during a large political conference in 2021 in response to, as he described them, increasing military threats under the US leadership. Other weapons systems he had announced were intercontinental ballistic missiles, ultrasonic weapons, spy satellites and multiple head missiles. Since then, North Korea has carried out a series of tests to acquire these weapons.

In the meantime, questions have arisen on how North Korea, a country under strict sanctions and limited financial resources, can ensure the necessary technologies and resources for the construction of nuclear submarines.

Moon, the submarine expert, estimated that North Korea may have received technological assistance from Russia to build a nuclear reactor to be used in the submarine in return for the supply of conventional weapons and troops to support Russian warfare.