The forthcoming meeting between Russian President Vladimir Putin and Japanese Prime Minister Shinzo Abe is not expected to yield any breakthrough in the two nations' territorial spat, the Kremlin said Wednesday.

"This issue will be touched upon in one way or another. But it is hardly possible to expect immediate and serious progress, because this topic is extremely sensitive and requires meticulous and constant work at the experts' level," Kremlin spokesman Dmitry Peskov told reporters.

He added that the meeting, scheduled to take place Friday in the Black Sea resort of Sochi, would help solve the issue.

Moscow and Tokyo have territorial disputes over the four Pacific islands, known as the Northern Territories in Japan and the Southern Kurils in Russia, which prevented the two sides from inking a peace treaty after World War II.

Relations between Russia and Japan have soured after the latter, together with the United States and the European Union, slapped sanctions on Russia in 2014 in response to Russia's role in the Ukraine crisis.

Putin is expected to pay a return visit to Japan later this year.