North Korea fired an unidentified ballistic missile toward the East Sea on Thursday, South Korea's military said.
The Joint Chiefs of Staff gave no further details, saying an analysis is under way.
The launch came just hours after the defense chiefs of South Korea and the United States condemned North Korea's troop deployment to Russia with "one voice" in the "strongest" terms during the allies' annual defense talks at the Pentagon on Wednesday.
North Korea last fired multiple short-range ballistic missiles on Sept. 18.