Russian President Vladimir Putin says that sanctions imposed on Russia over its actions in Ukraine are an obstacle to talks on a peace treaty with Japan.
Tokyo-Moscow relations have been hampered for decades by a dispute over a group of islands that Soviet troops seized at the end of the World War II. Russia calls them the Southern Kuriles; Japan calls them the Northern Territories.
Lingering tensions over the islands have prevented the two countries from signing a peace treaty to formally end the war.
Putin heads to Japan on December 15 to discuss the territorial dispute and economic cooperation with Prime Minister Shinzo Abe.
In an interview with Japanese media that was published on the Kremlin website on December 13, Putin said Moscow and Tokyo must agree on conditions for a peace treaty based on trust, adding that large-scale joint economic activities could help achieve that.
But he suggested sanctions were a significant obstacle.
"How are we going to further develop economic relations on a new, much higher...level, given the existence of a sanctions regime?" he asked.
On December 12, Japanese Trade Minister Hiroshige Seko ruled out any economic deals that would undermine unity of the Group of Seven (G7) economic powers on sanctions imposed on Russia after the annexation of Ukraine's Crimea Peninsula in March 2014.