Prime Minister Fumio Kishida said Tuesday that Japan views as unacceptable Russia's decision to suspend the countries' negotiations on a post-World War II peace treaty, in response to Tokyo's sanctions on Moscow over its invasion of Ukraine.
"Russia's actions are extremely unreasonable and totally unacceptable," Kishida told a Diet committee session. "We strongly protest."
Announcing the move on Monday, the Russian Foreign Ministry also said Moscow will halt a visa-free program allowing former Japanese residents to periodically visit four disputed islets off Hokkaido, and indicated Russia will withdraw from joint economic activities on the islands.
"It remains unchanged that Japan aims to solve the territorial issue and conclude a peace treaty with Russia," Kishida added.
The Russian invasion came as bilateral talks over the disputed islets, called the Northern Territories in Japan and the Southern Kurils in Russia, have stalled. The spat over the islets has prevented the two countries from signing a postwar peace treaty.
The Russian ministry has said the suspension of the negotiations stems from Japan's unilateral and unfriendly restrictions on relations over the conflict in Ukraine.
Kishida rejected the Russian claim, saying the current situation, including strict economic sanctions imposed by Western nations, Japan and other countries "originated in Russia's aggression against Ukraine," and Moscow is "trying to shift the responsibility for Japan-Russia relations."
Chief Cabinet Secretary Hirokazu Matsuno told a press conference that Senior Deputy Foreign Minister Shigeo Yamada explained Tokyo's stance to Russian Ambassador to Japan Mikhail Galuzin.
"To defend the foundation of the international order, we will continue to act in a resolute manner, united with the international community," Matsuno said.
In line with the United States, Britain and EU member nations, Tokyo has unveiled a series of sanctions against Moscow following the Feb. 24 invasion, including revoking Russia's "most-favored nation" trade status and freezing the assets of Russian President Vladimir Putin.
Japan maintains that the former Soviet Union illegally seized the four islands off Hokkaido, while Russia claims they were obtained legally as a result of World War II.