WASHINGTON - Ukrainian officials and analysts were quick to deny allegations that the Soviet-era Yuzhmash arms factory was a likely source of engine technology used in North Korea’s missiles and to redirect suspicions to Russia.

“It is a complex and bulky piece of equipment. It is simply not possible to supply it by bypassing export procedures,” said Mykola Sunhurovskyi, director of military programs at the Razumkov Center, a Kyiv think tank, to VOA’s Ukrainian Service. “What is possible, is for North Korea to obtain engines left behind after rocket dismantling in Russia. That could be possible. Meaning Russia could have kept the engines after it had taken apart the rockets, which had been slated for dismantling. Those could have been supplied.”

Michael Elleman, the author of a research report by the International Institute for Strategic Studies, says Pyongyang probably got illicit help from inside Ukraine. But Elleman acknowledges that help also could have come from Russia.

“There’s a lot of uncertainty as exactly how it could have been transferred. But, I think the likelihood is that the source is either in Russia or Ukraine,” Elleman told VOA’s Ukrainian Service.

Elleman says he first became aware of the possibility of Ukrainian technology when he noticed similarities in photos of North Korea’s September 2016 ground test.

“Well, according to two sources that I’ve spoken with, the modifications that we’ve seen in North Korea - that modified engine has actually been seen in Ukraine. That doesn’t mean it was done by Yuzhnoye [Yuzhmash’s design bureau], it could have been done by others or simultaneously. This was a product that was made long ago and it’s just been leveraged by unsavory types who were able to extract it from either Ukraine or Russia.”

‘Completely untrue’

Yuzhmash, the Ukrainian factory, called the claims “completely untrue” and said it had not produced military-grade ballistic missiles since Ukraine's 1991 independence from the Soviet Union.

"There is such a high level of confidentiality at the factory and in general it is ensured by a multi-level system of security, which includes not only Yuzhmash services, but also municipal and state services,” Yuzhmash Deputy Director Oleh Lebedev told Reuters TV.

Elleman was first quoted in The New York Times, which cited its own intelligence sources, saying that Ukraine was a likely source.

But Elleman says that even if Ukraine was a source, he sees no indication Ukrainian authorities would have been involved.

“I don’t believe the Ukrainian government was responsible in any way," he said. "And I suspect if it did occur in Ukraine, they may not have known. It’s likely they would not have known.”

Other analysts argue that North Korea can build its own engines and would not need help. But all agree it would be a good idea for Ukraine to allow an investigation.

“I believe in this situation, the MFA [Ministry of Foreign Affairs] of Ukraine needs to invite the international community, with the first invitation to be extended to the USA, to conduct an investigation here in Ukraine, as well as globally to study exactly how North Korea was able to develop its missile program, whether there is a Chinese connection or a Russian connection,” said the director of Ukraine’s National Institute for Strategic Studies and former head of Ukraine’s National Security and Defense Council, Volodymyr Horbulin.

“These are the two countries which maintain close relations with the DPRK [North Korea]. The proposal from Ukraine for such an investigation should put an end to constant attacks on our country by those who suggest that it is constantly trading in something banned by international accords or agreements,” said Horbulin.

FILE - A general view shows one of the work facili FILE - A general view shows one of the assembly facilities of Ukrainian state-owned aerospace company Yuzhmash in Dnipro (formerly Dnipropetrovsk), Ukraine, Oct. 21, 2014. The plant, which before 1991 produced missiles for the Soviet Union's arsenal, is seen as a possible source from which North Korea could have obtained advanced missile technology. The company's management denies the allegations. FILE - A general view shows one of the assembly facilities of Ukrainian state-owned aerospace company Yuzhmash in Dnipro (formerly Dnipropetrovsk), Ukraine, Oct. 21, 2014. The plant, which before 1991 produced missiles for the Soviet Union's arsenal, is seen as a possible source from which North Korea could have obtained advanced missile technology. The company's management denies the allegations.

Possible implications for U.S.-Ukraine cooperation

Ukrainian President Petro Poroshenko on Tuesday ordered an official inquiry into whether any missile engine technology could have been supplied to North Korea. Some experts in Ukraine worry that the allegations could affect any U.S. decision on whether to provide Ukraine with defensive weapons to fend off Russia-backed separatists.

“There’s ongoing discussion about the possibility to transfer lethal weapons to Ukraine,” noted the Ukrainian Center for Army’s Ihor Fedyk. “This story may have a negative impact on the process,” he told VOA’s Ukrainian Service.

There are concerns that other areas of bilateral cooperation, such as space programs, could be affected.

“America is our strategic partner, a very serious strategic partner, in space programs,” said the acting head of Ukraine’s State Space Agency, Yurii Radchenko. “It is not in our interests to harm relations with U.S. official agencies.”

U.S. State Department Spokeswoman Heather Nauert commented Tuesday, saying “We're certainly aware of those reports that have come out. That's an issue that we would take very seriously if that were to be the case."

"As a general matter, we don't comment on intelligence reports. Ukraine, though, we have to say, has a very strong nonproliferation record. And that includes specifically with respect to the DPRK,” Nauert added.

The allegations surfaced as North Korea threatens to send missiles near the U.S. island territory of Guam.

While Elleman's allegations are investigated, the North Korean government appears to have stepped back from its threat to Guam, saying it will wait to see what further actions the United States takes.