KYIV -- An anxious Kyiv has denied a story in The New York Times quoting an expert as saying North Korea may have obtained rocket engines from a Ukrainian state-run factory known as Yuzhmash, and instead alleges Russia is to blame.

Citing a report by the International Institute for Strategic Studies (IISS) and classified assessments by U.S. intelligence agencies, the Times on August 14 reported that Pyongyang's recent progress in its long-range missile program may be due to it having obtained advanced engine technology from Ukraine or Russia.

But the secretary of Ukraine's National Security and Defense Council (NSDC), Oleksandr Turchynov, insisted that could not be the case.

"Ukraine has never supplied rocket engines or any kind of missile technology to North Korea," he said in a strongly worded statement published on the council's website. "We believe that this anti-Ukrainian campaign was triggered by Russian secret services to cover their participation in the North Korean nuclear and missile programs."

Moscow has not commented on the report or Ukraine's allegations.

In its own statement, Yuzhmash said it "has never before and does not have anything to do with North Korean missile programs of a space or defense nature." The company also said the Times' report was "provocative" and "based on an incompetent expert opinion."

Michael Elleman, the expert and author of the report for the London-based IISS, told The New York Times that he believed the Yuzhmash missile factory, located in the eastern Ukrainian city of Dnipro, was "the most likely source of the engines" that powered North Korea's two intercontinental ballistic missiles in July.

As part of his analysis, Elleman speculated that Yuzhmash employees might have been motivated to send the rocket technology to Pyongyang because the plant had "fallen on hard times" financially amid political upheaval and conflict in recent years.

However, Elleman conceded that the North Koreans could have gotten the technology from Russia's state-run rocket company, Energomash, as well, something he reiterated on Twitter following publication of the report and a wave of public scrutiny.

As the report notes, the Yuzhmash factory is located near territory controlled by Russia-backed separatists in eastern Ukraine. It is also not far from the border with Russia, and amid the chaos of war, Ukraine's east has become a haven for illicit trade.

A Ukrainian security official who asked not to be named because of the sensitive nature of the issue said Ukraine had had success in tackling smuggling recently but had in the past struggled with keeping secrets from the rocket factory from leaking outside the country.

The Kyiv Post, citing local and international reports, said that North Korean spies had attempted to steal rocket technology from Ukraine in June 2012 and December 2015, in both cases from Yuzhmash. In 2015, the paper reported, Ukraine claimed to have detained and sentenced two North Korean diplomats from Belarus who had tried to photograph secret Yuzhmash documents relating to the construction of liquid-fuel rocket engines.

Elleman, speaking to the Times, suggested that could be the case here, saying, "It's likely that these engines came from Ukraine -- probably illicitly."

He added about the North Koreans and possible Ukrainian state involvement: "The big question is how many they have and whether the Ukrainians are helping them now. I'm very worried."

'It's A Russian Psyop'

The allegations of Ukraine's possible involvement in supplying Pyongyang with missile technology come at a particularly crucial moment for the country. U.S. President Donald Trump's administration is currently weighing whether to provide Kyiv with lethal weapons, including Javelin antitank missiles, to better defend against the Russia-backed forces it has been fighting in its east for more than three years.

That's one reason why Ukraine's security apparatus is "working to correct this information as fast as possible, based on facts," NSDC Deputy Secretary Oleksandr Lytvynenko told RFE/RL by phone.

Lytvynenko claimed Russian "psyops" -- or psychological operations, a term used to describe noncombative military operations -- played a role in the delivery of rocket technology to Pyongyang in order to cover the country's own participation in North Korea's missile program in a manner that could frame Ukraine, and possibly even in the dissemination of the IISS report itself.

He also pointed to Elleman's past work in Russia from 1995 to 2001, when he led a program aimed at dismantling obsolete long-range missiles, according to his biography on IISS’s website, as what he said was evidence of "ties" to Moscow. Lytvynenko provided nothing else as evidence for his claims.

Speaking to RFE/RL by phone from Washington, Elleman said he expected some to disagree with his report, but he was "shocked" by the Ukrainian response and allegations of working for Moscow.

"I don’t have any direct ties to the Russian government," Elleman said. "I've done work with Russians in the past. I’m no fan of [Russian President Vladimir] Putin, that’s for sure. He's a dictator and authoritarian and a destabilizing force throughout Europe and Asia and the Middle East.”

It was "disappointing" that Ukraine didn't respond to the report by initiating an investigation to determine whether it is in fact a Yuzhmash engine that was obtained by North Korea, Elleman added.

Asked if the NSDC or any other security body would be investigating whether the rocket technology could have been obtained illegally from someone in Ukraine and smuggled to Pyongyang, Lytvynenko said that "could not happen," suggesting there would be no inquiry.

"I do not believe there are stupid Ukrainians who can sell the engine to North Korea. Russia played with [the] Kims," he said, referring to the family of North Korean leader Kim Jong Un and Moscow's backing in some cases of the tightly controlled state.

Some Experts Not Convinced

It is not only the Ukrainians denying the findings in Elleman's report. Joshua Pollack, editor of The Nonproliferation Review and a senior research associate at the Middlebury Institute of International Studies at Monterey, California, told RFE/RL via direct message on Twitter that he believed "the report is bogus."

"The [U.S. government] is convinced that [North Korea] makes its own rocket engines. It has sanctioned Iran for participating in the development of the 80-ton engine that Elleman and others link to the Soviet RD-250," he said, referring to the specific technology alleged to have come from Ukraine or Russia in the IISS report.

Moreover, Pollack said, that engine was not used in the North Korean Hwasong-12 and Hwasong-14 rockets launched this summer. "They use a different, smaller main engine, and also have four small steering engines around it," he added.