Long-awaited summit talks between Prime Minister Shinzo Abe and Russian President Vladimir Putin were set to kick off on Thursday at a hot spring resort in the prime minister's home prefecture of Yamaguchi.

Still, the onsen rapprochement is unlikely to produce a major breakthrough in the postwar territorial row between the two nations over four islands off Hokkaido. Instead, it could lead only to economic cooperation deals with Russia.

Putin's interview with the Yomiuri Shimbun and Nippon TV on Tuesday underscores the challenging nature of the issue. Ahead of his first visit to Japan in 11 years, Putin made it clear that sanctions imposed on Russia by Japan and other western powers after Russia annexed Crimea in 2014 are a hindrance in the negotiations, according to a transcript released by the Kremlin.