South Korea on Wednesday strongly denounced Japan’s fresh claim to the Dokdo islets, calling in Tokyo’s deputy envoy in Seoul in the latest flare-up in tension.

“Historically, geographically and legally speaking, the islets -- Dokdo -- clearly belong to us and we urge Japan to stop repeating its unreasonable claims and face up to the history,” Korea’s Foreign Ministry said in a statement released shortly after a high-ranking Japanese official took part in an event annually held there to tell the public the islets are Japan’s.

The ministry summoned Naoki Kumagai, deputy chief of mission at the Japanese Embassy, to deliver the complaint in person and highlight the seriousness of the matter, amid efforts still underway to resolve a historical dispute involving Koreans forced to work for Japanese companies during World War II.

Foreign Minister Park Jin has said the two countries are close to a compromise, suggesting the Korean and Japanese leaders would have to make the final call themselves, after months of working-level talks. “It’s too hard to tell definitively when that would take place,” Park’s ministry said.