The ceremony was attended by the country’s leader Kim Jong-un, TASS reported.
According to the report, it was the country’s first submarine carrying tactical nuclear weapons.
The submarine is now being readied for sea trials.
In his speech on the occasion, Kim Jong-un called nuclear weapons an important component of the country’s naval forces.
"We are full of determination to continue to further demonstrate how advanced our submarines and surface shops are, and we will continue [the process of] rearming our fleet with nuclear weapons," the Voice of Korea quoted him as saying.
North Korea carried out several test-launches of submarine-launched ballistic missiles (SLBMs) in the past.
SKH/PR