South Korea's presidential office said on Monday it will demand the U.S. to take appropriate action regarding reports of the United States' alleged spying on its top security officials when details of the matter are confirmed, Yonhap news agency reported.

The presidential office also said checking facts is a top priority and that potential distortion of intelligence and third-party interference in the process cannot be ruled out, another news outlet, YTN, reported.

Media reports showed a set of leaked Pentagon documents shared on social media revealed that U.S. intelligence services eavesdropped on conversations at the South Korean presidential office in early March regarding whether to provide weapons support to Ukraine.

"Once the two countries finish figuring out the situation, we plan to request appropriate measures from the U.S. if necessary," Yonhap reported, citing a presidential official, who noted that the reports on the leaked documents have not yet been verified as true and that a U.S. government investigation is under way.

"If there are forces trying to exaggerate this incident ahead of the South Korea-U.S. summit or distort it to undermine the alliance, they will face the resistance of many people," the official told Yonhap.

The summit mentioned refers to the meeting between South Korean President Yoon Suk-yeol and U.S. President Joe Biden on April 26.

According to Yonhap, the official also denied accusations from the main opposition Democratic Party that the alleged eavesdropping resulted from the Yoon administration's hasty relocation of the presidential office.

"In terms of security at the presidential office building, we prepared perfectly during the relocation process, and though I can't divulge details, we're still carrying out regular checks on areas that you're concerned about, and there have been no problems until now," the official told Yonhap.

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South Korea to discuss 'issues raised' from leaked documents with U.S.

(With input from agencies)

(Cover: South Korean President Yoon Suk-yeol addresses a Cabinet meeting at the presidential office in Seoul, South Korea, April 4, 2023. /CFP)