"We believe that the launch was carried out from a submarine... At the moment, based on the general data recorded, we believe that [the SLBM] is the same type as the one tested by North Korea in October, 2021," the military source told reporters on Saturday.
Earlier on Saturday, South Korea's Joint Chiefs of Staff said that the projectile launched by Pyongyang at around 14:07 local time (05:07 GMT) off the port city of Sinpo toward the Sea of Japan was likely an SLBM.
The Saturday launch was the 15th missile test conducted by North Korea this year.
The last time that Pyongyang announced the testing of a submarine-launched ballistic missile was in October 2021.