U.S. intelligence officials said on Tuesday, Censor.NET reports citing Reuters.
The assessment disputes a new study by the London-based International Institute for Strategic Studies that said that the engines for a nuclear missile North Korea is developing to hit the United States likely were made in factories in Ukraine or Russia and probably obtained via black market networks.
The New York Times cited the study on Monday. The newspaper's report said that classified assessments by U.S. intelligence agencies mirrored the IISS finding.
"We have intelligence to suggest that North Korea is not reliant on imports of engines," one U.S. intelligence official told Reuters. "Instead, we judge they have the ability to produce the engines themselves."
The U.S. officials did not disclose any details of what underpinned the assessment on the high-performance liquid-fueled engines, called RD-250's.
Ukraine denied that it had ever supplied defense technology to North Korea. The Ukrainian factory cited in The New York Times, state-owned Yuzhmash (Pivdenmash), said it had not produced military-grade ballistic missiles since independence from the Soviet Union in 1991.
Earlier, The New York Times cited an expert analysis and classified assessments by American intelligence agencies stating that North Korea's success in testing an intercontinental ballistic missile that appears able to reach the United States was made possible by black-market purchases of powerful rocket engines probably from a Ukrainian factory with historical ties to Russia's missile program.
National Security and Defense Council Secretary Oleksandr Turchynov said in a commentary Ukraine always obliges its international obligations, so the state defense and airspace industries have never delivered weapons and military technologies to North Korea.
Pivdenmash (the alleged producer of the missiles featured in NYT article) also said in a commentary that the article in The New York Times was a provocation.