A South Korean military official says North Korea may be exaggerating or making false claims over what it calls a new "tactical nuclear attack submarine."
An official of South Korea's Joint Chiefs of Staff told reporters on Friday that an analysis of the external features of the vessel indicates that the North has modified a conventional submarine.
The official added that its bridge and other parts appear to have been enlarged to carry a missile.
The official went on to say that the submarine is "not in the form of being capable of normal operation," but no information was provided to back this up.
North Korea's ruling Workers' Party newspaper said earlier on Friday that the submarine's launch ceremony was held on Wednesday. North Korean leader Kim Jong Un reportedly attended the event.