Japan said Wednesday it would protest South Korea's decision to name a naval ship after islets it controls that are also claimed by Tokyo.
South Korea launched a 14,000-ton class multipurpose naval vessel Tuesday named after islets that lie in the Sea of Japan between Japan and the Korean Peninsula.
The islets, surrounded by rich fishing waters, are called Tok-do in Korean and Takeshima in Japanese and have been a main source of recent animosity between the two countries.
"It is truly regrettable that the name was used on the vessel despite repeated requests by the Japanese government not to do so," Chief Cabinet Secretary Hiroyuki Hosoda told reporters Wednesday. "I expect the (Foreign) ministry to protest strongly once again."