MOSCOW (AP) — Russia's foreign minister warned Japan Saturday against expecting a quick breakthrough in the territorial dispute between the two nations ahead of President Vladimir Putin's upcoming visit to Japan.

Sergey Lavrov said after talks with his Japanese counterpart Fumio Kishida that the settlement would require a painstaking work. He added that its rendering in the media "in either a confrontational spirit or by encouraging excessive expectations of a quick progress" wouldn't help.

The disagreement over the Pacific islands, seized by the Soviet Union in the final days of World War II, has kept the two countries from signing a peace treaty formally ending their wartime hostilities.

Japan's Prime Minister Shinzo Abe has been pushing for progress in the dispute over the islands, called the southern Kurils by Russia and the Northern Territories by Japan.

The sparsely inhabited islands lie just north of the Japanese island of Hokkaido, in an area rich in natural resources, and they also serve as a strategic vantage point for the Russian military. Last month, Japan protested after Russia announced the deployment of new anti-ship missiles on Pacific islands to the Kurils.

Abe's two visits to Russia this year have led many to believe Tokyo and Moscow are moving toward a breakthrough, Kishida met with Putin Friday to deliver Abe's message to Putin.

Putin said at the start of his meeting with Kishida that Russia is working on Abe's proposals to expand ties between the two countries, but he made no mention of the Kuril islands.

Lavrov on Saturday offered a similar indication that Moscow sees a progress in economic ties as key condition for success of talks on the islands.

"The more we act together, the more broadly we develop our ties in all spheres without exclusion searching for a balance of interests of Russia and Japan ... the easier it will be for us to solve the most difficult problems," he said.

Russia has pledged adherence to a 1956 declaration in which the Soviet Union said it was ready to hand two of the four Southern Kuril islands to Japan, but Lavrov underlined that it stipulates that the signing of a peace treaty should come first.