Guests offer a moment of silence during a memorial ceremony for the laborers who worked in the Sado mines in Japan's Niigata Prefecture, Sunday, as seats reserved for Korean guests remained empty. The Korean officials announced the previous day their intention to skip the event, citing unresolved disagreements with Japan over the ceremony's arrangements. AP-Yonhap

Korean officials skipped Japan's memorial service held near the Sado mine site, Sunday, in an apparent protest against Tokyo's "insincerity" in addressing the dark history related to the site, where approximately 1,500 Koreans were subjected to forced labor during Japan's 1910-45 colonial rule.

Critics view that this latest incident, which could reignite historical disputes over the forced labor issue, could undermine the Yoon Suk Yeol government's efforts to foster closer cooperation with Tokyo.

Diplomatic friction with Japan has been rare under Yoon, whose administration has prioritized mending ties with the neighboring nation after years of strained relations over historical grievances.

The memorial service, held at the Aikawa Development Center on Sado Island in Niigata Prefecture, was attended by Japanese government officials and members of civic groups, with no Korean officials present. Akiko Ikuina, a parliamentary vice minister of Japan's foreign ministry, represented the government.

Organizing the memorial ceremony was part of an agreement reached between Seoul and Tokyo during the UNESCO World Heritage designation of the site in July. Korea's consent was critical to the site's inscription, and in return, Japan pledged to acknowledge the history of Korean forced labor through an annual ceremony honoring those who worked there.

Korea's top envoy to Japan, Park Chul-hee, and several descendants of forced labor victims had been expected to attend the event.

However, on Saturday, just one day before the planned event, Korea's Ministry of Foreign Affairs abruptly announced its withdrawal, citing unresolved disagreements with Japan over the ceremony's arrangements.

Akiko Ikuina, a parliamentary vice minister of Japan's foreign ministry, lays a wreath during a memorial ceremony for the laborers who worked in the Sado mines at Niigata Prefecture, Japan, Sunday. Yonhap

The ministry said it would instead host a separate memorial service near the site on Monday morning, with the families of forced labor victims who had already landed in Japan. A total of nine families arrived there for a three-day stay, with their expenses covered by the Korean government.

While officials in Seoul did not provide a detailed explanation for the sudden decision, it appears to be closely related to Japan's pick to send Ikuina as its representative.

Her attendance, announced by the Japanese foreign ministry on Friday, immediately sparked controversy due to her previous visit to the Yasukuni Shrine, a site seen by Seoul as glorifying Japan's wartime aggression.

Ikuina's involvement drew criticism that her presence was inappropriate for the ceremony meant to honor Korean victims of forced labor.

During the memorial, Ikuina delivered a speech in which she stated that "laborers from the Korean Peninsula worked in dangerous and harsh conditions in the mines, far from their homeland, thinking of their beloved families." But the speech did not address the coercive nature of Japan's forced mobilization of Koreans to the mines.

The Japanese government expressed regret over Korea's lack of participation.

"We have been working in cooperation with local officials who are hosting the event and have conducted polite communication with the Korean government. It is regrettable that Korea decided not to attend," the Japanese Embassy in Seoul said in a statement, Sunday.

The embassy also said it believed Ikuina had not visited the Yasukuni Shrine since taking office. However, previous Japanese reports indicate that she visited the shrine on Aug. 15, 2022, shortly after being elected.

Visitors look at a display at the Sado mine site on Sado Island in Niigata Prefecture, Japan, Saturday. AP-Yonhap

Critics have pointed out that Japan's lack of sincerity and Korea's subsequent boycotting of the memorial service were foreseeable, as tensions surrounding the ceremony had been simmering for months.

Initially scheduled for August, the event was delayed for months, with the date and venue confirmed only in November. The lack of clarity about key details fueled further speculation of discord between the two governments.

Last Wednesday, Korea's foreign ministry held a closed-door briefing to confirm its participation but disclosed little information about crucial arrangements, such as the representatives from both countries and the content of the memorial addresses.

By Thursday, with just three days left, officials were still unable to provide specifics. A follow-up briefing scheduled for Friday was canceled abruptly, hours after Japan announced Ikuina's attendance.

Lee Jae-woong, spokesperson for the Ministry of Foreign Affiairs, speaks during a press conference at Government Complex Seoul, Thursday. Yonhap

The main opposition Democratic Party of Korea (DPK) labeled the fallout from the memorial as a "diplomatic disaster."

"This no longer seems like mere diplomatic incompetence but rather a calculated plan by a pro-Japanese administration," DPK spokesperson Rep. Kang Yu-jung said Sunday, denouncing the Yoon government for making too many concessions in its diplomacy with Japan.

"The ceremony was intended to honor our ancestors who endured suffering. Yet Japan chose to send a representative who has glorified wartime aggressors. The Yoon administration, realizing this far too late, made a hasty decision to withdraw just a day before the event."

A Gwangju-based civic group supporting the victims of Japan's forced labor blamed the "diplomatic disgrace and humiliation" on the Yoon administration's apparent pro-Japanese stance.

Foreign Minister Cho Tae-yul stressed the importance of preventing the issue from escalating into a broader diplomatic conflict, particularly as the two nations prepare to mark the 60th anniversary of bilateral ties next year.

"Strengthening cooperation between Korea and Japan is crucial for our national security. Both countries should ensure that such issues do not disrupt the overall momentum of bilateral relations," Cho said in an interview with MBN, Saturday.