This is the second launch of the country this week and the fifteenth since the beginning of the current year.
The Joint Chiefs of Staff (JCS) announced the launch, the North's 15th show of force this year. Details were not immediately known.
Military authorities here presume the launch involves a ballistic missile, Yonhap news agency reported.
The latest launch came after the North launched a ballistic missile Wednesday.
Although North Korean officials have not yet commented, the Japanese Defense Ministry has said the missile may be a ballistic missile.
MA/PR