Seoul denies classified info leak after US protests minister's NK nuclear facility remarks

Unification Minister Chung Dong-young answers lawmakers’ questions during a plenary session of the Foreign Affairs and Unification Committee at the National Assembly in Seoul, Wednesday. Yonhap

The United States has reportedly conveyed its intention to partially restrict intelligence sharing on North Korea following remarks by South Korea’s Unification Minister Chung Dong-young, who publicly identified Kusong, North Pyongan Province, as a suspected third nuclear facility in the North during a National Assembly session in March.

Despite the Ministry of Unification’s denial of the U.S.’ intentions to restrict information sharing, security experts have raised concerns that the issue could affect trust in intelligence cooperation between the two allies.

According to local media reports Friday that cited diplomatic sources from both countries, U.S. officials lodged strong protests through multiple channels following Chung’s remarks, expressing concern that sensitive information may have been publicly disclosed. The reports added Washington was dissatisfied that intelligence shared with South Korea appeared to have been made public and suggested the U.S. may have already taken steps to limit certain aspects of North Korea intelligence cooperation.

The ministry pushed back against the reports, noting that Chung’s remarks were derived from publicly available information, including reports by U.S.-based think tanks, rather than classified intelligence.

“Minister Chung referred to Kusong based on open-source information from international research institutions and media reports,” ministry deputy spokesperson Chang Yoon-jeong said during a press briefing. “He also mentioned Kusong during his confirmation hearing in July last year.”

Unification Ministry deputy spokesperson Chang Yoon-jeong speaks during a press briefing at Government Complex Seoul, Friday. Yonhap

Chang added that the ministry had sufficiently explained the background of the remarks to the U.S. side and Washington had expressed understanding.

“We are not aware of any protest from the U.S. side,” she said, adding that the ministry maintains regular communication with the U.S. Embassy in Seoul.

When asked whether the U.S. had formally notified Seoul of plans to scale back intelligence sharing, Chang said, “The ministry is not aware of any such measures.”

While the ministry sought to downplay the issue, some experts warned that the situation could have broader implications for bilateral trust.

“It is difficult to draw conclusions based on speculation,” an expert who requested anonymity told The Korea Times. “However, if the reports are accurate, they could have longer-term implications for intelligence cooperation between the two countries, as mutual trust may be affected.”

Security analyst Yang Uk at the Asan Institute for Policy Studies also questioned the necessity of the minister’s remarks.

“I don’t understand why such a statement needed to be made,” he said. “It seems like an unnecessary comment that may have gone beyond what was appropriate.”

During a March 6 session of the National Assembly’s Foreign Affairs and Unification Committee, Chung cited comments by Rafael Grossi, head of the International Atomic Energy Agency, claiming that uranium enrichment facilities exist in Yongbyon, Kusong and Kangson. However, Grossi did not mention Kusong in the speech referenced by Chung.

The ministry reiterated that the minister’s understanding was based on open-source analyses, including a 2016 report by the Institute for Science and International Security. The report suggested that an early centrifuge research and development facility may have been located near Panghyon Air Base — an area within Kusong located about 45 kilometers west of Yongbyon — and could have housed up to 300 centrifuges.

Later on Sunday, local media reported that Washington has already partially restricted the sharing of satellite intelligence on North Korea with Seoul in response to Chung’s remarks, with the measure reportedly taking effect about a week ago.

The Ministry of National Defense did not confirm whether any changes had been made to intelligence sharing between the two countries. It said, “South Korea and the United States maintain a close intelligence sharing system based on a firm combined defense posture.”