Japan has expressed regret over South Korea's decision not to send a delegation to Japan's Sado mine memorial ceremony set for Sunday.

The Japanese Foreign Ministry on Sunday voiced regret in a statement released by the Japanese Embassy in Seoul.

The embassy said that Tokyo had been in "polite communication" with Seoul over the event in cooperation with the organizer, calling the South Korean decision "regrettable."

The embassy said the event will be held as planned later on Sunday at a facility near the mines, despite Seoul's boycott.

The South Korean Foreign Ministry said on Saturday that it came to the decision as there is no sufficient time to iron out differences between the two sides without specifying the nature of their disagreement.

The decision was apparently in response to Tokyo's plan to send Parliamentary Vice-Minister for Foreign Affairs Akiko Ikuina to the event.
 
Ikuina in 2022 visited the controversial Yasukuni shrine, which honors Japan's war dead, including Class-A war criminals.

Japan announced earlier that the ceremony will be held on Sado Island, off its west coast, to keep its promise to honor the victims who were forced into hard labor at the mine complex during Japan's colonial occupation of Korea.