Japan decried as "absolutely unacceptable" on Wednesday Russia's extension of an entry ban to 30 more citizens, among them a foreign ministry spokesperson, after Tokyo's sanctions over Moscow's nearly four-year-old war in Ukraine.

Following similar moves by Western nations, Japan had placed additional sanctions on Russian companies, individuals and other entities in September, while lowering its cap on Russian seaborne crude.

Russia's foreign ministry issued on Tuesday a list of Japanese added to those facing "indefinite" prohibition. The new names included the spokesperson, Toshihiro Kitamura, as well as journalists and academics.

Japan has protested against the "regrettable" move, Chief Cabinet Secretary Minoru Kihara told a briefing on Wednesday, adding that people-to-people exchanges between the two countries remain important.

He accused Moscow of shifting the blame for its invasion of Ukraine.

Moscow has taken similar measures against Japanese officials and civilians in retaliation for sanctions.

Japan, however, continues to import energy from the far-eastern Russian island of Sakhalin, despite calls by the United States for allies to sever ties to pressure Moscow.

Asked how Britain's ban on insurance for Russian gas shipping would affect energy from Sakhalin and whether Tokyo would increase sanctions on Moscow, Kihara declined to comment.

Japan will take appropriate steps to achieve peace in Ukraine while securing its national interests, he added.