Russia's Foreign Ministry said Thursday that a peace treaty with Japan to formally end enmity between the two nations dating back to World War II is a long-term prospect.

"This work is continuing and will continue. It is complicated and may take a long time," Russian Deputy Foreign Minister Alexander Alexeyev was cited by Interfax news agency as saying.

Alexeyev's comment came on the eve of the visit of Japanese Foreign Minister Nobutaka Machimura to Moscow which is expected to pave the way for Russian President Vladimir Putin's scheduled trip to Japan later this year.

Russia and Japan have still to sign a peace treaty to formally end wartime hostilities due to a continuing dispute over four islands to the north of Japan seized by the Soviet Union in the closing days of the World War II.

Russia recently offered to return to Japan 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.

Japan has demanded the return of all four islands -- which stretch from northern Japan to the tip of Russia's Kamchatka peninsula in the Far East -- saying it is the premise for signing the peace treaty.

During Machimura's visit to Moscow, both sides are expected to discuss the half-century-old territorial dispute, preparation work for Putin's tour to Japan and bilateral economic cooperation, the Itar-Tass news agency reported.

Other international issues including the Democratic People's Republic of Korea and Iraq are also expected to be discussed.

Source: Xinhua