The JCS detected an unspecified number of missile launches around 9:00 a.m. local time (00:00 GMT) over waters northeast of the North Korean port city of Wonsan, the report said.
The report quoted the JSC as saying that the South's military "has been closely coordinating with the United States to monitor additional signs of North Korea's provocations" while "strengthening our monitoring and vigilance."
The missile firing marked the fifth cruise missile launch in 2024, the report said.