Defence experts claim North Korea's recently unveiled 'new' submarine is actually a refurbished Soviet relic.
Footage emerged of despot Kim Jong Un inspecting the vessel yesterday, as North Korean propagandists boasted about their latest naval asset.
However some analysts noticed that the vessel was strikingly similar to the Type-033 Romeo, a Soviet submarine from the 1950s.
Defence expert Joseph Dempsey pointed out that the North Korean shared the same stern and bow as the Type-033.
Mr Dempsey added that the modifications to the vessel seemed to have turned it into a ballistic missile submarine.
Kim was said to have showed great satisfaction with the 'powerful submarine'.
"In a country where the country's east and west is surrounded by the sea, the operational capability of submarines is an important component of national defence," Kim said.
North Korea "should continue to develop our national defence capability by putting great efforts in developing naval arms equipment, including submarines", he added.
Kim tasked defence and scientific officials accompanying him with achieving even more in submarine technology, state media said.
In May Kim Jong-un watched through binoculars and was pictured laughing and smiling as North Korea test-fired two missiles possibly using a new weapons system.
North Korean state media published photos of the dictator looking jovial while sat in a chair behind a wooden desk, where he was surrounded by senior military officials in uniform.
Kim has ordered his military to move into "full combat posture" and boost its strike capability amid heightened tensions with the US.
Images released by state-run KCNA - a day after the long-range "strike drill" in Kusong - show a missile being fired from a launcher vehicle.
Kim gave the order to launch the missiles, said KCNA, and it described the training ground as "boiling" and "burning like fire" during the second drill in five days.
