A U.N. environment conference opened Monday with its chairman pushing for progress in efforts to rescue a 1997 global-warming treaty that President Bush has abandoned.
Delegates from about 180 countries gathered for a new round of bargaining over the treaty, which is meant to combat climate changes that many scientists fear will wreak havoc on the planet.
"It's crucial that we bring our four years of work to completion," said chairman Jan Pronk, the Dutch environment minister. "We need to get good results for ourselves, for the ministers and the public."
European nations have pledged to push ahead with the Kyoto Protocol without the U.S., saying it could join later. But recently Japan, which could sink the accord if it withdraws support, has also begun to waver.
Environmental groups urged international pressure on Japan.
"The protocol is clearly hanging by a thread, and that thread is only as strong as the Japanese government," Greenpeace climate expert Bill Hare said. "Japan's indecision is casting a big cloud over the negotiations here."
The accord calls for rich countries to cut emissions of greenhouse gases. Contentious rules for achieving that goal, however, were left open.
Bush renounced the Kyoto pact in March, saying it was based on questionable science and is unfair because it exempts large developing countries such as China and India.