Story highlights Russia signs a resolution to give names to 5 formerly nameless islands on the Kuril chain

Japan responds by lodging a formal protest

(CNN) Japan has lodged a formal protest against Russia's naming of five uninhabited islands in the disputed Kuril chain, north of Japan's Hokkaido island.

"Such moves go against our country's stance and is extremely regrettable," said Japan's chief Cabinet secretary Yoshihide Suga during a press conference Tuesday.

The 56-island Kuril chain has been a sore spot in Japan-Russia relations for the past 72 years.

The Kuril Islands sit on routes the Russian navy can use to get into the open Pacific.

The chain became part of Russia with the dissolution of the Soviet Union in 1991 but Japan claims four islands it refers to as the "Northern Territories."

The long-standing territorial dispute has prevented both countries from signing a peace treaty to end World War II.

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