Japan has filed a protest with South Korea over a plan to place a "comfort women" memorial statue on disputed islets in the Sea of Japan, Chief Cabinet Secretary Yoshihide Suga said.

The plan is "extremely deplorable and unacceptable in light of our position on the sovereignty of Takeshima," Chief told a news conference Tuesday, referring to the islets controlled by South Korea but claimed by Japan.

A group of South Korean local assembly members announced Monday they plan to place the statue on the islets — called Dokdo in South Korea — according to South Korean media, following weeks of heightened tensions over the issue of the women procured for Japanese military brothels before and during World War II.