Photo provided by Korean Central News Agency (KCNA) on May 30, 2017 shows the test-firing of a ballistic missile. (Xinhua/KCNA)

MOSCOW, Aug. 18 (Xinhua) -- Russia's Roscosmos state space corporation and its subsidiaries do not cooperate with the Democratic People's Republic of Korea (DPRK), Roscosmos said in a statement on Friday.

It said Roscosmos and its subsidiary companies have been strictly observing the requirements of the Russian legislation and international arms control and non-proliferation regimes, including the 1987 Missile Technology Control Regime (MTCR), as well as the requirements and restrictions imposed by UN Security Council resolutions.

The New York Times said in a report on Monday that the DRPK's success in testing ballistic missiles was made possible by black-market purchases of rocket engines "probably from a Ukrainian factory with historical ties with Russia's missile program."

Following the publication, later in the day, Oleksandr Turchynov, the Secretary of the Ukrainian National Security and Defense Council, denied any Ukrainian involvement.