The White House on Saturday declined to confirm the comments were from US officials, but said discussions continued about what the G-8 leaders will say.

“Our challenge and opportunity is in developing an approach that is appropriate and conducive to all these major emitting countries,” said Dana Perino, a White House spokeswoman.

German Chancellor Angela Merkel, holding the rotating presidency of both the G-8 bloc of industrialised nations and the European Union, wants the June meeting to agree to targets for cuts in greenhouse gas output and a timetable for a major agreement on emissions reduction to succeed the Kyoto Protocol.

But unattributed comments written on a draft summit communique, which Greenpeace said were written by US officials and handed to it by an undisclosed third party, suggest the White House has major reservations.

“The US still has serious, fundamental concerns about this draft statement,” the notes on the document read. “The treatment of climate change runs counter to our overall position and crosses multiple ‘red lines’ in terms of what we simply cannot agree to.”

The 27 EU members have agreed to cut greenhouse gas emissions by 20 per cent by 2020 — building on Kyoto, which runs through 2012 — and by 30 per cent if a broader international agreement can be reached.

Though Merkel and outgoing British leader Tony Blair — who made climate change a key priority for his final weeks in office — have pressed US President George W Bush to back a new agreement, the document claimed the White House is “fundamentally opposed” to many of the European objectives.

The US, the world’s biggest polluter, did not ratify the Kyoto agreement through which developed countries agreed to cut emissions by 5 per cent below their 1990 level by 2012.