South Korea to Probe Circumstances Around Reported Leak of Classified U.S. Documents

SEOUL—A South Korean official said the government was investigating the circumstances around a leak of highly classified U.S. documents that appeared to show intelligence based on intercepted communications of U.S. allies, including discussions among Seoul officials about concerns over selling ammunition to the U.S. that could end up in Ukraine.

South Korea’s first priority was to establish the facts, an official from the country’s presidential office said on Monday, adding that the reports of the intelligence leak hadn’t been confirmed. Once that is done, South Korea “plans to request, if necessary, the U.S. to take reasonable measures,” the official said.