Plans by the Russian military to hold live-fire exercises off the disputed Northern Territories prompted a rebuke by Tokyo late last week, the chief government spokesman said Monday.
The drills are planned for waters around Kunashiri, a land mass that is clearly visible from the shores of Hokkaido.
"We've lodged a protest through a diplomatic channel because the drills are linked to Russia's military buildup on the Northern Territories," said Chief Cabinet Secretary Yoshihide Suga.