The JCS said it is analyzing the projectile's specifications and range.
If the projectile is confirmed to be a ballistic missile, it would mark a provocation nine days after the launch on the 3rd.
North Korea earlier fired a ballistic missile from the Wonsan area toward the East Sea on the 3rd. The missile detected at the time flew more than 700 kilometers. North Korean state media later said the country "launched a hypersonic intermediate-range ballistic missile under the observation of State Affairs Commission Chairman Kim Jong-un," claiming a range of 1,000 kilometers.
The latest show of force comes four days after South Korea's military disclosed a test launch of a domestically developed hypersonic glide vehicle. The military revealed the first HGV launch on the 8th as a response to a North Korean landmine explosion in the Demilitarized Zone.