Japanese Prime Minister Shinzo Abe is set to leave for Russia on Monday for talks with President Vladimir Putin.
Abe is determined to promote discussions on signing a peace treaty that would include a solution to the issue of four Russian-held islands.
Russia controls the four islands. Japan claims them.
The Japanese government maintains the islands are an inherent part of Japan's territory. It says the islands were illegally occupied after World War Two.
During his two-day stay in Russia, Abe is expected to meet Putin on Tuesday.
It will be the 25th summit between the two leaders. They met in Argentina last month.
Abe and Putin agreed in November to accelerate negotiations on a peace treaty based on a 1956 joint declaration stating that two of the four islands would be handed over to Japan after the conclusion of a bilateral peace treaty.
But last week's meeting between Japanese Foreign Minister Taro Kono and his Russian counterpart Sergey Lavrov highlighted differences over the territorial issue.
The Russian side has urged Japan to recognize Russian sovereignty over the islands as a result of World War Two. It has also expressed concern and frustration over the Japan-US alliance and Japan's joining Western nations in imposing sanctions on Russia.
The Russians have nonetheless shown a willingness to continue negotiations with Japan.
Abe is expected to try to find common ground, relying on his relationship of trust with Putin.