The draft, dated May 5, shows that Washington wants to make the Major Emitters grouping set up by U.S. President George W. Bush last year the main forum for climate action, taking the initiative away from the smaller group of rich nations.

"We would be prepared to address mid-term goals in the G8 only if the Major Economies Leaders Statement does not do so and only in a way that points to the need for commitments from major emerging economies," said a U.S. comment in the draft.

In the draft for the July 7-9 summit at Hokkaido in Japan, the U.S. endorses expansion of civil nuclear power as a low carbon technology and says biofuels are not the main cause of the recent surge in world food prices.

The Major Economies Meeting -- also known as the Major Emitters Meeting -- will take place in Japan on the sidelines of the G8 summit.

It groups the United States, Australia, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, South Korea, South Africa and Britain, as well as the European Union and the United Nations.

The G8 summit is due to formally adopt the informal goal agreed a year ago that global carbon emissions should be reduced by 50 percent below 1990 levels by 2050.

There is also rising pressure to set mid-term goals for 2020 to 2030 as well as a way of reinforcing the long-term target.

But by taking the initiative away from the G8, which has made most of the running, and linking a deal to agreement on action by booming emitters like China and India which have so far rejected targets, Washington is in effect blocking any movement.

Reinforcing that position, another U.S. comment in the draft declaration said: "We will not agree to long-term language without mid-term language."

The U.S. which only recently acknowledged that global warming was at least in part due to burning fossil fuels for power and transport, also rejected proposals by the G8 for an industry-by-industry approach to carbon curbs.

Here again it said the Major Emitters, not the G8, was the appropriate forum for any such declaration.

"We are prepared to address it in the G8 only if the MEM Leaders Declaration fails to capture the sectoral approach idea," it said.

In supporting civil nuclear power expansion and sustainable biofuels production such as cellulosic ethanol, the United States is also supporting its own agenda.

"The expansion of nuclear energy would help to mitigate the adverse impacts of climate change and would provide the greater global energy security by diversifying supply options," said the U.S. comment in the draft text.

It called for agreement in the Doha round of world trade talks on eliminating barriers to trade in green goods and services, adding that a voluntary deal within the G8 would not be the right approach.