Japan reaffirmed on Friday its unchanged position on the return of all four islands seized by Russia, a thorny issue that hinders the two neighbors from dealing a peace treaty that formally ends wartime enmity.

Japan insists that the peace treaty could only be signed after Russia returns to Japan all the four islands seized by the Soviet Union in the closing days of World War II, visiting Japanese Foreign Minister Nobutaka Machimura said in Moscow after talks with his Russian counterpart Sergei Lavrov.

Russia has offered to return only two of the islands -- known as the southern Kuriles in Russia and the Northern Territories in Japan -- after the conclusion of a peace treaty, citing a joint declaration signed in 1956 by the Soviet Union and Japan.

Machimura said both sides agree to resolve the half-century-old territorial dispute on the basis of mutual trust and comprehensive cooperation, but Japan and Russia have differences on the understanding of the 1956 declaration, Itar-Tass news agency reported.

He noted that if Japan accepted the return of the two islands, a peace treaty should have been signed in 1956 instead of a declaration.

The Japanese minister said Tokyo does not expect that the territorial dispute can be resolved by only one visit by leaders of both nations, but more negotiations are necessary.

"We would have to hold several meetings. We understand that this issue is quite complicated, but this does not mean that it will have to be resolved by the generations to come," Machimura was cited by Interfax news agency as saying.

"We are not talking about deadlines, but we believe that this issue must be resolved extremely quickly. This is really our strong feeling, and we will make every effort to resolve this problem," he vowed.

Machimura arrived here Thursday for discussions paving ways for Russian President Vladimir Putin's trip to Japan by the end of this month.

After talks with Russian Industry and Energy Minister Viktor Khristenko, Machimura confirmed Tokyo's interest in taking part in building the Russian oil pipeline from East Siberia to the Pacific coast.

Friday's discussion "primarily dealt with the involvement of Japanese companies in the implementation of this project," said Khristenko.The Russian minister did not specify how large the Japanese investments might be, saying that the issue will be determined by companies of both sides.

Source: Xinhua