Russia's geopolitical commemorations on claims to a former Indigenous Japanese territory have inflamed tensions amid an ongoing dispute over four disputed archipelagic islands.
The 70th anniversary of the 1956 Japan-Soviet joint declaration, held on Monday, has seemingly hardened Russia's stance on the Southern Kuril Islands group.
President Vladimir Putin had accepted using the historic pact to formally end World War II hostilities as a basis for a future peace treaty talks towards territorial concessions first back in 2018.
That declaration included an agreement for Moscow to hand back the disputed Shikotan and the Habomai islands that Japan calls the Northern Territories, which holds deep cultural significance for the Ainu people.
The Japanese claim is also a part of two other non-Indigenous islands in a dispute for Etorofu and Kunashir.
Shikotan and Habomai islands, just north of Hokkaido, have historically been a traditional home for the Indigenous Ainu since the 15th century, however three Russian naval voyages in the mid-18th century accelerated Russian control of the Kurils leading to full occupation in August 1945.
Sakhalin island, an undisputed Russian territory which is barely 45 kilometres from Hokkaido, has been central to recent commemorations on October 19 every year throughout the past decade.
Moscow, since claiming sovereignty, has settled ethnic Russians across the Kurils — which includes on Shikotan and the Habomai islands — totalling around 20,000 people today.
The last known Ainu residents were displaced after the Soviet occupation in 1945, having been forcibly relocated to Hokkaido's northern coast.
The Ainu claimed Indigenous status over their historical continuity with Shikotan and the Habomai islands for 500 years before Japan's national expansion existed, shielding the Ainu's distinct culture, traditional spiritual beliefs and their unique language from the rest of the country without feeling pressured to assimilate.
A 2023 Hokkaido survey recorded around 11,450 people had claimed Ainu ancestry nearly 80 years on from suffering displacement and disease. Another 300 Ainu people are calculated to live today on Sakhalin in Russia.
The eventual return of the Japanese Indigenous culture back to their ancestral lands appears more uncertain than ever before.
"We take seriously the fact that the Northern Territories issue remains unresolved," Japan chief cabinet secretary Minoru Kihara said during a news conference on Monday.
"We'll continue necessary communication with the Russian side and work toward breakthrough."
Tokyo condemned President Putin's visit to the Kurils in August, with the country's Prime Minister, Sanae Takaichi, saying "both historically and under international law" the territory was integral to its sovereignty while calling the Russian leader's pre-commemoration trip "incompatible with Japan's consistent position".
It comes after Moscow first suspended peace treaty talks in 2022 amid Russia first invading Ukraine.
Russia has walked away from the negotiation table altogether in response to Japan joining the West in sanctions against it, only strengthening Moscow's firm belief that the territorial dispute has been settled.
On a recent trip to Russia's Far East, President Putin told senior officers of the Russian Navy's Pacific fleet that Moscow's resistant control of the disputed islands was due to Japan's self-inflicted deterioration of their bilateral relations.
The Putin administration has designated Japan as an "unfriendly" state over Tokyo's stance on Russia's conflict in Ukraine.
It has since decided to scrap agreements on visa-free exchanges involving the disputed islands.
