The Joint Chiefs of Staff(JCS) said that North Korea fired what it claims to be a space launch vehicle southward on Wednesday morning.
The South Korean military is analyzing the details of the launch, including the type of the projectile and the range.
North Korea earlier announced that the launch would occur between May 31 and June 11, before the regime's top-ranking military official made a formal announcement on Tuesday of plans to send up the regime's first military spy satellite next month.
The North previously launched what it called a space launch vehicle on February 7 in 2016.
Marking the tenth North Korean launch this year, the latest provocation comes about 40 days after the firing of the new Hwasong-18 solid-fuel intercontinental ballistic missile on April 13.