Japanese Prime Minister Shinzo Abe will meet with Russian President Vladimir Putin in the Black Sea resort of Sochi to deepen ties and try to resolve a long-running territorial dispute.
Tokyo-Moscow relations have been hampered for decades by a dispute over the Kurile Islands, which Soviet troops seized at the end of the World War II.
Lingering tensions over the islands have prevented Japan and Russia from ever signing a peace treaty to formally end the war.
"This is a complex, multifaceted issue that can only be resolved in a manner acceptable to both sides through an even deeper partnership between the two countries," Putin's chief foreign-policy adviser, Yury Ushakov, said.
Japanese Foreign Minister Fumio Kishida said last month that the two countries had agreed to start negotiations on signing a peace treaty.
His Russian counterpart, Sergei Lavrov, said Russia wanted to "move forward" in relations, but was not prepared to budge on the "result of World War II."
In signs Russia is not about to cede control over the Kuriles, Russian Prime Minister Dmitry Medvedev last year visited one of the islands, home to some 19,000 Russians, and Moscow recently built new compounds for troops stationed there.
Still, Putin said during a public phone-in last month that he thinks "a compromise could be found at some point -- and it will be found" on the territorial dispute.
"Immediate serious progress" is unlikely at the Sochi meeting, Kremlin spokesman Dmitry Peskov said, but Moscow hopes it will establish a "constructive atmosphere in bilateral relations."
Tensions have also risen more recently as Japan joined Western states in imposing sanctions on Russia over its aggression in Ukraine.
The Japanese press reported that U.S. President Barack Obama earlier this year asked Abe not to go through with the visit with Putin because of the sanctions and related Western efforts to isolate Moscow.
But Abe noted that European and U.S. leaders had maintained contacts with Moscow despite the sanctions, so he will too.
"I am going to Russia, with which I want to build the relations that would make it possible for us to cope with various international problems together," he said.
The White House had no comment on the matter this week.
Putin said last month he appreciated Abe's willingness to visit despite "pressure from partners, particularly the United States."
The leaders are expected to discuss a repeatedly postponed visit by Putin to Japan this year. Japanese media reported that Abe may invite the Russian leader to his home prefecture of Yamaguchi.
Moscow plans to invite Abe to take part in its Eastern Economic Forum in Vladivostok on September 2-3.
The Kremlin said they were also set to discuss economic ties. Moscow says trade turnover between Russia and Japan last year fell 31 percent due to low oil prices.
Abe will later this month host a summit of the Group of Seven advanced industrial countries. Russia was essentially kicked out of what was once the Group of Eight because of its annexation of Crimea.
With reporting by AFP and TASS