The Times: Improved North Korean KN-23 ballistic missiles are now comparable in accuracy to Russian Iskander missiles
Military Expert Tucker: Russia Helped North Korea Modernize its Armed Forces
KN-23
Bulgarian Military: North Korean Missiles Are as Accurate as Soviet OTR-23 Oka
OTR-23 Oka was decommissioned after the signing of the INF Treaty with the United States
Defence blog: North Korea supplied Russia with over 100 ballistic missiles with Western components
The DPRK authorities circumvent sanctions and purchase the necessary parts for weapons