It is necessary to recall that the DPRK has previously conducted a ground test of high-power solid-fuel rocket engine and stage separation. The relevant photo image was released by KCNA on March 24, 2016.

STATEMENTBy DPRK ADS SpokespersonAnother crucial test was successfully conducted at the Sohae Satellite Launching Ground from 22:41 to 22:48 on December 13, 2019.Our defence scientists were greatly honored to receive warm congratulations from the Central Committee of the Workers' Party of Korea on the spot.The research successes being registered by us in defence science one after another recently will be applied to further bolstering up the reliable strategic nuclear war deterrent of the Democratic People's Republic of Korea.(KCNA - December 14, 2019)