Kim Hyok Chol, North Korea's delegate in nuclear talks with the United States, enters a hotel in Hanoi, Vietnam, on Feb. 21, 2019. (Yonhap/EPA-EFE)

A report in a Seoul-based newspaper Friday claimed that North Korea had executed its chief nuclear negotiator, Kim Hyok Chol, shortly after the breakdown in talks with the United States in Hanoi.

However, officials and diplomats from the United States to Asia, many of whom were not authorized to give their names, said that they had no knowledge of the story, or expressed caution and even outright skepticism about it.

North Korea watchers have been here before. There is no doubt that North Korea would be willing to execute an official perceived to have failed its leader. In 2013, South Korea’s intelligence service was the first to report the execution of Kim Jong Un’s uncle, Jang Song Thaek, who had been purged from the leadership ranks. Subsequent media reports — now believed to be false — said that he was killed by being fed to pack of wild dogs.

It is part of a spotty track record by South Korean media on reporting purges and state-ordered killings in the reclusive north.

The Chosun Ilbo newspaper — which also had Friday’s purported scoop — reported in 2013 that Hyon Song Wol, a North Korean artist it described as Kim Jong Un’s “ex-girlfriend,” had been executed in public over accusations that she and other performers had sold pornographic videos. At least part of that story later proved to be demonstratively untrue: Hyon made a two-day visit to Seoul in January 2018, very much alive.

Neither the South Korean government nor the U.S. government has publicly confirmed the report about Kim Hyok Chol. Secretary of State Mike Pompeo, asked about the report Friday, said only that the administration had seen it.

“We’re doing our best to check it out,” Pompeo told reporters while traveling in Germany. “I don’t have anything else to add to that today.”

A Western diplomat, who spoke on the condition of anonymity as he was not authorized to speak on the record, said he was “very skeptical.” U.S. officials said that the administration had not heard of Kim Hyok Chol’s execution before the story came out and had not been able to confirm it Friday. The officials also spoke on the condition of anonymity to discuss intelligence gathering.

Pyongyang’s political machinations are notoriously difficult to decipher, presenting Washington with a significant challenge in understanding the motivations and reactions of the North Korean elite.

Former CIA analyst Sue Mi Terry said it would “not be remarkable, not unusual, not even surprising” if the executions happened, but that it was “100 percent” a problem for the United States if it was unsure of who North Korea’s top nuclear negotiators were.

“We refer to North Korea as the hardest of the hard targets,” said Bruce Klingner of the Heritage Foundation, also a former CIA analyst, referring to the difficulty of getting accurate intelligence about the country.

The Chosun Ilbo reported that Kim Hyok Chol was shot at Mirim Airport in March along with four other senior officials on charges of spying for the United States. The newspaper cited a single unnamed source “who knows about North Korea.”

The Chosun Ilbo also reported that Kim Yong Chol, a top North Korean nuclear negotiator, had been sentenced to hard labor and ideological reeducation. Kim Yong Chol had been one of the most visible members of the North Korean negotiating team, even meeting with Trump at the White House.

Kim Hyok Chol has been the counterpart of Stephen E. Biegun, the Trump administration’s chief envoy to North Korea, and he was responsible for prep work for the summit between Trump and Kim which took place in late February.

There had been speculation that Kim Hyok Chol, a relatively obscure career diplomat before the summit, was demoted after it.

Among defector and activist groups, there had been considerable talk of executions of North Korean officials after the Hanoi meetings. Rimjin Gang, a website run from Japan that claims to have contacts within North Korea, reported May 5 that four foreign ministry officials were rumored to have been executed for selling information to Americans before the summit. None of the reported executions has been confirmed.

The Chosun Ilbo is one of South Korea’s major newspapers and follows North Korean events fervently (after Kim Jong Un’s summit with South Korean President Moon Jae-in last May, they asked experts to look at the North Korean leader’s shoes in a bid to gauge his height).

But the newspaper also has a strongly conservative editorial line and is a frequent critic of outreach to North Korea. It has reported a number of sensational stories about North Korea that later proved to be unfounded.

The high level of secrecy in North Korean society allows rumors to spread quickly.

Nevertheless, the idea that Kim Hyok Chol could have been purged or demoted seems conceivable. Neither he nor Kim Yong Chol has been seen in public since the Hanoi summit.

National security adviser John Bolton said last week that neither the U.S. nor South Korea governments had “heard much” from the North Korean regime since the breakdown of the Hanoi summit, and that there had been no response to Biegun’s efforts to restart talks.

Klingner said that negotiations between Pyongyang and both Washington and Seoul appeared to have hit an impasse, “perhaps because no one is there to answer the phone.”

Lee Hye-Hoon, who heads South Korea’s parliamentary intelligence committee, said late Friday that the National Intelligence Service was hearing contradictory accounts of Kim Hyok Chol’s fate, with some saying he could have been purged and some saying not, but concluded that there was insufficient evidence to say definitively that he had been purged, let alone executed.

Terry, now a fellow at the Center for Strategic and International Studies in Washington, said it was unlikely that intelligence services could say with high confidence that the executions happened, unless they had intercepted communications — a possibility that she said was “really rare.”

But they may well have found indications or suggestions that a similar purge had happened. The North Korean state newspaper Rodong Sinmun railed in a Thursday commentary against “traitors and turncoats who only memorize words of loyalty toward the Leader and even change according to the trend of the time.”

Terry also noted that two other North Korean officials, Choe Son Hui and Ri Yong Ho, had given the news conference in Hanoi after the talks collapsed, with Choe also recently promoted to vice foreign minister.

“There’s no question that Kim Hyok Chol and Kim Yong Chol are not part of the negotiating team anymore. They were in charge, and they failed,” Terry said. “In the North Korean system, somebody has to take the fall.”

Denyer reported from Tokyo, and Hudson reported from Seoul. Min Joo Kim in Seoul contributed to this report.