(Seoul) A “significant number” of classified US intelligence documents on South Korea, which have leaked in recent weeks among others, have been “falsified”, the South Korean presidency said on Tuesday.

This leak, which according to the Pentagon poses a “very serious” risk to the national security of the United States, has caused diplomatic embarrassment. Some of the leaked documents do indeed appear to indicate that Washington collects intelligence on its allies, such as Israel and South Korea.

According to press reports, several documents show concerns among senior South Korean national security officials, who fear that weapons and ammunition produced in their country will end up being used in Ukraine. Such an eventuality would constitute a violation of Seoul’s policy of not selling any weapons to countries at war.

During a telephone call on Tuesday, the American and South Korean defense ministers, however, estimated that “a significant number of the documents in question have been falsified”, according to a press release from the South Korean presidency.

Dozens of photographs of the documents have been circulating for at least several weeks on social media and messaging services such as Twitter, Telegram and Discord.

The Pentagon said it is working to determine if the documents are genuine, and said at least one appears to have been manipulated.

The leak prompted US officials to reassure allies such as South Korea, which provided humanitarian and non-lethal aid to Ukraine after the Russian invasion of the country began in 2022.

The revelation of alleged talks about Ukraine between senior national security officials has sparked criticism in South Korea about the vulnerability of communications within the country’s key administrations, such as the presidency.

President Yoon Suk Yeol’s office defended itself on Tuesday, however, saying it had “ironclad security” and that the wiretap accusations were “insane lies”.

Mr. Yoon is due to make a state visit to the United States in April.