Prime Minister Yoshiro Mori is expected to visit Russia in February, despite his willingness to visit the country before the end of the year, the Russian Information Agency reported Saturday.
The two countries have agreed to arrange the visit for February and preparations have begun, the news agency said, quoting diplomatic sources.
The sources said that Tokyo has become "realistic" in its approach to resolving a decades-long territorial row with Russia.
Japan had been sticking to the terms a 1997 agreement that committed the two countries to attempt to settle the dispute and conclude a peace treaty before the end of this year, the agency said, but Tokyo has started to show flexibility and is listening to proposals by Russia.
The dispute -- involving the islands of Etorofu, Kunashiri, Shikotan and the Habomai islets, all east of Hokkaido -- has prevented the two countries from signing a peace treaty.
The islands were seized by the Soviet Union at the end of World War II.
Mori agreed during a meeting in Brunei in November with Russian President Vladimir Putin that he would visit Irkutsk, eastern Russia, possibly by the end of the year if any progress is made in peace treaty negotiations.