TOKYO — Japanese Prime Minister Yoshiro Mori will cancel an expected visit to Russia, virtually ending hopes that the two nations will be able to sign a World War II peace treaty within the year, domestic media reported Wednesday.

The Tokyo Shimbun daily said Mori would cancel the visit, proposed by President Vladimir Putin during their September meeting, due to his domestic political troubles and amid fading hopes of solving a sticky territorial dispute with Moscow.

However, Ryuichiro Yamazaki, a Japanese Foreign Ministry spokesman, said nothing had been decided.

"The articles are only making predictions," Yamazaki said. "We never agreed that the visit would take place within the year."

The two nations agreed in 1997 to try to clinch a formal peace pact this year.

But after the September summit meeting held in Tokyo, Putin signaled that the deadline for signing the treaty was quietly being dropped.

The dispute over four tiny Russian-held islands that Japan wants back is the sole obstacle to a treaty. Soviet troops seized the islands, located off Japan’s main northern island of Hokkaido, at the end of the war in 1945.

Yamazaki said the early signing of a peace treaty would depend on progress made during a visit by Japanese Foreign Minister Yohei Kono to Moscow from Wednesday and the scheduled meeting of the two leaders during the sidelines of the Asia Pacific Economic Cooperation forum in Brunei later this month.