A major South Korean daily newspaper reported on Friday that North Korea had executed its special envoy to the United States. This execution comes as part of a larger purge of nuclear negotiators instigated by Kim Jong-un after the failed second summit with the United States.

The envoy, Kim Hyok-chol, was executed by firing squad in March at an airfield outside Pyongyang, reported South Korea’s largest paper, Chosun Ilbo. According to an anonymous source, Chosun Ilbo claimed that Mr. Kim was charged with being “won over by the American imperialists to betray the supreme leader,” and sentenced to death. The newspaper also said that four top-level officials from North Korea’s Foreign Ministry were also executed.

The South Korean Government has been unable to verify these claims, as Chosun Ilbo has remained tight-lipped about who leaked the information, most likely in an attempt to maintain the safety of its contacts. North Korea has not released any information about any executions or purges, and since it remains one of the world’s most isolated countries, no government has been able to confirm the reports of the South Korean newspaper.

When questioned about the North Korean executions, American Secretary of State Mike Pompeo replied that the United States was looking into the matter. This is the same response that the government has given out for the past few weeks when asked about the executions.

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Negotiations between the United States and North Korea are currently stalled after the leaders of the two countries failed to reach an agreement during their summit in Hanoi, Vietnam this February. Both President Donald Trump and North Korean leader Kim Jong-un refused to give in to the demands of the other, leaving them both in a diplomatic stalemate. Since then, North Korea has resumed its missile tests, worrying both leaders in East Asia, such as Japanese Prime Minister Shinzo Abe, as well as leaders at home, such as National Security Advisor John Bolton. However, Trump has reported that he is “not personally bothered” by these tests, signaling that maybe the country isn’t necessarily headed towards war.