US seeks G8 climate text changes
Washington objects to the draft's targets to keep the global temperature rise below 2C this century and halve greenhouse gas emissions by 2050.
The draft, prepared by the German G8 Presidency, says action is imperative.
Japanese news organisations recently reported that Prime Minister Shinzo Abe's government was also planning to push fellow G8 members for tough targets.
As well as objecting to mention of targets for global temperature rise and greenhouse gas emissions, Washington is also seeking to remove a section acknowledging that the UN is the "appropriate forum" for agreeing further action.
"It lies in the hands of Prime Minister Blair and Chancellor Merkel, whether it's all sweetness and light or whether they are prepared to stand up and say 'I'm sorry, but the rest of the world is moving in a different direction from you'," he said.