Russia says it has built four new military barracks in the Kuril islands, angering Tokyo on Tuesday with whom it has been locked in a decades-long row over the archipelago in the Sea of Japan.
Moscow and Tokyo are still technically at war, with neither side historically prepared to budge on a dispute over the ownership of the islands seized by the Soviet Union in the closing days of World War II.
Soldiers will be able to move into the new dormitories by the end of the year, the Russian defence ministry said in a statement on Monday.
The ministry said 188 families of contracted soldiers can settle in the housing complexes. It added that the new barracks were part of the "development of military and social infrastructure" on the islands.
Japanese foreign minister Taro Kono told a news conference on Tuesday morning that Tokyo would protest the move.
Two of the Russian barracks are on Iturup island and the other two are on Kunashir island.
Russian television channel Zvezda, run by the defence ministry, published a video of the new housing, saying nursery schools and sports centres were also being built for the soldiers' families.
In November, Russia and Japan agreed to accelerate talks to formally end World War II hostilities, using a Soviet-era peace declaration as their starting point and throwing into doubt the fate of four disputed islands.
The 1956 peace declaration restored diplomatic ties but Tokyo and Russia stopped short of signing a formal peace treaty due to the territorial row.
At the time, Russia offered to give Japan the two smallest islands in the strategically-located Kuril chain, occupied by Soviet troops in 1945, in exchange for agreeing to a treaty and Moscow keeping the bigger islands.
But this idea was rejected by Japan, which still claims the entire chain.