South Korea and the United States have reportedly concluded that North Korea’s recent launch was of an existing Hwasong-15 intercontinental ballistic missile(ICBM), not a new Hwasong-17 ICBM.

According to multiple sources in the military and government on Sunday, the allies reached the conclusion after a thorough analysis of the North Korean missile launched from the Sunan airfield in Pyongyang on Thursday.

According to the analysis based on the allies' intelligence assets, the ICBM launched last week had two engine nozzles, resembling the Hwasong-15. The Hwasong-17 has four nozzles.

The intelligence analysis also suggested the engine combustion time of the first-stage rocket was similar to that of the Hwasong-15.

A local security expert said it is possible that North Korea tested a standard Hwasong-15 or a modified one to compensate for the failed launch on March 16.