U.S. Focus of Climate Discussions

BALI, Indonesia -- Any agreement hammered out by a massive United Nations climate change conference starting in Indonesia this week would not make sense without the participation of the United States, the world's top emitter of greenhouse gases, the UN's climate chief said Sunday.

Delegates from 190 nations will gather on the resort island of Bali on Monday for the largest global warming conference ever, bringing more than 10,000 people together for two weeks of marathon discussions, including Hollywood stars, former U.S. Vice President Al Gore, fishermen and drought-stricken farmers.

World leaders will attempt to launch negotiations leading to a replacement for the Kyoto Protocol, which expires in 2012. Among the most contentious issues will be whether emission cuts should be mandatory or voluntary and how to help the world's poorest countries adapt to a worsening climate.

Yvo de Boer, general-secretary of the UN Framework Convention on Climate Change, said the role of the United States was "critical" in the discussions.

"To design a long-term response to climate change that does not include the world's largest emitter and the world's largest economy just would not make any sense," he told reporters.

The United States said ahead of the Bali talks that it was eager to launch negotiations, but it has been among the industrialized nations leading a campaign against mandatory emission cuts.