DNIPRO, Ukraine (AP) — The head of Ukraine's top rocket-making company is rejecting claims that its technologies might have been shipped to North Korea.

KB Yuzhnoye chief Alexander Degtyarev voiced confidence that employees haven't been leaking know-how to Pyongyang, according to remarks published Tuesday by the online site Strana.ua.

The New York Times reported Monday that North Korea's rapid progress in making ballistic missiles potentially capable of reaching the United States was made possible by black-market purchases of powerful rocket engines, probably from the Ukrainian plant in Dnipro. Ukrainian officials deny the claim.

Degtyarev acknowledged that Pyongyang had displayed a keen interest in the plant before. He mentioned a 2012 incident, in which two North Koreans posing as trade representatives allegedly tried to steal technologies from the plant, but were arrested and convicted of espionage.