People watch news on North Korea's ballistic missile launch at Seoul Station in central Seoul, Oct. 23, 2025. Yonhap

North Korea fired at least one ballistic missile toward the East Sea on Wednesday, South Korea's military said, in a move seen as a protest against an upcoming combined military exercise between the South and the United States.

The Joint Chiefs of Staff (JCS) said it detected the missile launched from the Wonsan area on the east coast at around 6 a.m.

The JCS said it has stepped up surveillance and vigilance against possible additional launches.

"South Korea, the U.S. and Japan maintain a full readiness posture by closely sharing information regarding North Korea's ballistic missile launch," it said.