Japan's leader met with Russia's outgoing and incoming presidents Saturday, seeking Moscow's support for global environmental initiatives before the Group of Eight summit.

Prime Minister Yasuo Fukuda discussed Japan's initiatives against global warming, as well as ways of mending ties with Russia, during his meetings with President Vladimir Putin and his president-elect Dmitry Medvedev.

At the opening of talks, Putin said: "In the last two or three years, we managed to improve the quality of our relations. We are continuing the dialogue on a peace treaty."

Japan and Russia have not signed a formal World War II peace treaty because of a dispute over four Pacific islands that Soviet forces seized in the last days of the conflict.

Fukuda said he would "like to give new momentum to our relations."

Afterward, Fukuda met with Medvedev.

"First and foremost, we will discuss the G-8 summit in Japan," Medvedev told Fukuda at their meeting in a government residence just outside Moscow. The G-8 summit will be an early international appearance for Medvedev after he takes office May 7.

"The summit is the most appropriate place to discuss environment-related issues," Fukuda said.

Russia's support was critical to the survival of the 1997 Kyoto Protocol, under which industrialized countries have to cut their collective greenhouse gas emissions. Russia signed the treaty in 2004.

Since the 1991 collapse of the Soviet Union, Russia's industrial activity has declined sharply, putting Russia's emissions 30 percent below the baseline and meaning it can sell unused emissions credits to countries that have exceeded their limits.

Fukuda declared that Japan is ready to commit itself to a new specific emissions reduction target, along with other major emitters, after the expiration of the Kyoto treaty.

This is Fukuda's first visit to Russia since his election in September.