Ukraine's Ambassador to Japan Ihor Kharchenko has denied a recent claim that a state-owned plant in his country leaked rocket-engine technology possibly used by North Korea to develop intercontinental ballistic missiles.

"From 1991, I don't think we ever had any type of connections with North Korea. We never had an embassy there. I don't know about any type of, any single type of cooperation with North Korea," Kharchenko said Friday in an interview.

He was reacting to an Aug. 14 report published by a missile expert at a British think tank who cited evidence that North Korea "has acquired a high-performance liquid-propellant engine from illicit networks in Russia and Ukraine."