The U.S. government estimates that North Korea produced a total of 20 Daepodong Two ballistic missiles prior to 2006.

The report on the North’s ballistic missile threats against the U.S. was issued by the Congressional Research Service on Wednesday.

According to the report, the North began producing Daepodong Two missiles in 2005 and produced a total of 20 by 2006.

The report quoted experts as saying that if a rocket is loaded with the Daepodong Two, its current range could be extended to 67-hundred kilometers, but that North Korea would need to shed around 300 kilograms from any warhead it could load on the missile in order for it to be able to reach U.S. territory.