"The emerging consensus is that the solution to climate change is the advancement of technology," James Connaughton, Bush's senior environmental adviser, told reporters.

"And there is also consensus that you need growing economies to pay for that technology. These are not a trade-off: if you don't have a growing economy, you don't have the resources to pay for the new new technologies," he added.

Connaughton, who has been in Beijing to prepare for the Washington talks and a preceding Asia-Pacific summit in Sydney, said he was encouraged by what he called a very significant shift on environmental policy in recent years in China.

"This is wonderful to see, and America stands ready to assist on technology, to assist in innovative financing and assist in standards and practices so that together we can grow our economies ... in a more sustainable way," he said.

China, like the United States, is outside the 1997 Kyoto Protocol on reducing carbon emissions. Negotiators will meet in Bali in December to see whether progress can be made towards replacing the pact, which expires in 2012. Washington signed the Protocol but did not ratify it.

Connaughton said China would soon replace the United States -- if it has not already done so -- as the world's largest emitter of greenhouse gases, which trap heat near the Earth's surface and so bring on global warming. He also acknowledged the country's severe air and water pollution.

"I think there are great challenges in China, but I've been encouraged at the innovation at the governmental level in tools for promoting compliance," he said.

Noting that it had taken the United States a generation to implement strong environmental protection policies, Connaughton said: "We did it in less than 30 years. China can do it in less than 30 years, and that's what we look forward to."

Connaughton sidestepped a question on whether China would meet its goal of reducing energy intensity -- the amount of energy that goes into each unit of output -- by 20 percent between 2006 and 2010. Last year, energy intensity fell just 1.33 percent.

"With any of these goals, what matters most is that they are reasonably ambitious, they are technically justified and we have close monitoring to see what is working and what is not working," he said.

Washington has put cooperation on environmental technology at the heart of its top-level "strategic economic dialogue" with Beijing. The two have agreed to develop 15 large-scale coal mine methane capture projects in China in the next five years.

Cooperating on clean coal technology was especially important because 70 percent of the future increase in greenhouse gases will come from coal burnt for power generation, Connaughton said.