North Korea has unveiled what appears to be significant strides in its pursuit of a nuclear-powered submarine. The nation’s state-controlled media shared images featuring North Korean leader Kim Jong Un alongside his daughter, who is speculated to be his successor, as they examined what seems to be a nearly finished submarine hull.

According to the Korean Central News Agency (KCNA), the official state media outlet of North Korea, Kim and his daughter toured a shipyard to assess the construction progress of a submarine described as an 8,700-ton-class nuclear-propelled vessel, as reported by The Associated Press. There are indications from Pyongyang that this submarine could be equipped with nuclear armaments. Kim Jong Un has emphasized that developing such a submarine is a pivotal move in advancing and modernizing his country’s naval capabilities.

The publication of these photos on Christmas Day marks the first update from North Korean state media regarding the nuclear-powered submarine since March. Previous images primarily depicted the vessel’s lower sections, according to the AP. Notably, KCNA did not specify the date when these newly released images were captured.

In an undated photograph provided on Thursday, December 25, 2025, by the North Korean government, leader Kim Jong Un is seen inspecting the construction of a nuclear-powered submarine at an undisclosed site in North Korea. Independent media were not permitted to report on the event shown in this image distributed by the North Korean government. The authenticity of the image cannot be independently confirmed. (Korean Central News Agency/Korea News Service via AP)

Moon Keun-sik, a submarine expert from Seoul’s Hanyang University, shared with the AP that the images of a nearly completed hull suggest that many critical components are likely already installed, as submarines are typically constructed from the inside out. Nonetheless, the exact extent of Pyongyang’s progress remains uncertain.

“Displaying the full vessel now suggests that most equipment is already in place and it is nearing readiness for launch,” remarked Moon, who also has experience as a submarine officer in the South Korean navy, to the AP. He further mentioned that North Korea’s submarine could potentially be prepared for sea trials in a matter of months.

In this undated photo provided Thursday, Dec. 25, 2025, by the North Korean government, its leader Kim Jong Un, third left, visits a shipyard as he inspects a nuclear-powered submarine under construction at an undisclosed location in North Korea. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified. (Korean Central News Agency/Korea News Service via AP)

While at the shipyard, Kim condemned South Korea’s efforts to develop its own nuclear-powered submarine as an “offensive act,” despite the fact that President Donald Trump has backed Seoul’s push toward the technology. Kim said South Korea’s efforts violate North Korea’s security and maritime sovereignty, according to the AP.

In October, during his tour of Asia aimed at securing investments, Trump said that the U.S. would share technology with South Korea that would allow it to build a nuclear-powered submarine. The president posted on Truth Social that the vessel would be built in Philadelphia.

In this undated photo provided Thursday, Dec. 25, 2025, by the North Korean government, its leader Kim Jong Un inspects a nuclear-powered submarine under construction at an undisclosed location in North Korea. Independent journalists were not given access to cover the event depicted in this image distributed by the North Korean government. The content of this image is as provided and cannot be independently verified. (Korean Central News Agency/Korea News Service via AP)

“South Korea will be building its nuclear-powered submarine in the Philadelphia shipyards, right here in the good ol’ U.S.A. Shipbuilding in our country will soon be making a BIG COMEBACK,” the president wrote.

The White House underscored the point when it released a fact sheet in November which directly referenced Washington and Seoul’s efforts to “further our maritime and nuclear partnership.”