"Without binding limits and reduction targets for industrial countries, climate change will not be stopped," said Sigmar Gabriel, adding the United States and Europe had to lead the way in cutting greenhouse gas emissions.

"The motto of his speech is: losing instead of leading," said Gabriel, a Social Democrat in conservative Chancellor Angela Merkel's coalition government.

Bush on Wednesday unveiled plans to cap US emissions by 2025, toughening an existing target to slow the growth of emissions by 2012 but critics say the world needs tougher action to combat global warming.

The United States is the world's top greenhouse gas emitter. Germany is the world's sixth largest CO2 emitter and its efforts to reduce emissions have stagnated since the mid-1990s.