In unusually harsh language, Bush administration negotiators took issue with the German draft of the communiqué for the meeting of the Group of 8 industrialised nations, complaining that the proposal ‘‘crosses multiple red lines in terms of what we simply cannot agree to.’’

‘‘We have tried to tread lightly, but there is only so far we can go given our fundamental opposition to the German position,’’ the American response said.

Germany, backed by Britain and now Japan, has proposed cutting global greenhouse gas emissions by 50 percent by 2050. Chancellor Angela Merkel of Germany, who will be the host of the meeting in the Baltic Sea resort of Heiligendamm next month, has been pushing hard to get the Group of 8 to take significant action on climate change.

It had been a foregone conclusion that the Western European members of the Group of 8—Germany, Italy, France and Britain—would back the reductions. But on Thursday, Prime Minister Shinzo Abe of Japan threw his lot in with the Europeans, and proposed cutting carbon emissions as part of a new framework to replace the Kyoto Protocol, whose mandatory caps on gases end in 2012.

‘‘The Kyoto Protocol was the first, concrete step for the human race to tackle global warming, but we must admit that it has limitations,’’ Abe said at a conference in Tokyo. He specifically called on the United States and China, the biggest producers of carbon emissions, to lead the fight against global warming.

The United States has refused to ratify the Kyoto Protocol because of concerns about damage to the American economy. Bush administration officials have also balked because China and India are not part of it. The push back by the Bush administration over the German proposal has left many European diplomats furious. ‘‘The United States, on this issue, is virtually isolated,’’ one European diplomat said and then added, ‘‘with the exception of other big polluters.’’

Both Merkel and Prime Minister Tony Blair of Britain have, in private talks with President Bush, pushed for the United States to agree to the European proposal.

Kristen A. Hellmer, a spokeswoman for the White House on environmental issues, said: ‘‘All the G-8 countries are committed to pursuing an agreement. We just come at it from different perspectives.’’

A clearly disappointed Merkel, speaking to Germany’s lower house of Parliament on Thursday, sought to lower expectations that Bush would agree to the more ambitious agenda sought by Europe and Japan. ‘‘I can say quite openly that, today, I don’t know whether we will succeed in that at Heiligendamm,’’ she said.

The United States, with less than 5 percent of the world’s population, produces between a fifth and a quarter of the world’s emissions, according to government data.

Emissions in Europe and the United States have been slowing of late, with a slight drop in the United States in 2006. But much more growth is forecast by various agencies on both sides of the Atlantic and particularly in Asia.