STOCKHOLM - Swedish Prime Minister Fredrik Reinfeldt called on China to set a tougher target of cutting greenhouse gas emissions after 2020 as its part of a U.N. climate change agreement to be negotiated in Copenhagen.

China, which recently overtook the United States as the world's biggest carbon dioxide emitter, has said it will cut its C02 emissions per dollar of economic output by a notable margin by 2020 compared with 2005..

But it has resisted calls for quantifiable cuts which the European Union, among others, hopes will be the basis for a United Nations climate treaty to be agreed in the Danish capital in December.

My message to China is this: raise your ambitions so that emissions peak by 2020 at the latest and then fall, said Reinfeldt, whose country holds the rotating EU presidency.

We know that China has all the requirements for success and I hope that concrete commitments will be announced at the conference in Copenhagen, he said in an article published in the Dagens Nyheter newspaper on Tuesday.

Reinfeldt, who met President Barack Obama on Monday to discuss climate change, also called on the United States, other developed countries and India -- which he will visit this week -- to do their part.

Preparatory talks for the Copenhagen meeting on December 7-18 are bogged down in disputes about how to share out curbs on emissions between rich and poor nations, and how to raise billions of dollars to help developing countries adapt to climate change.

Reinfeldt admitted that many people had already written off Copenhagen as a failure and that all the details of a deal might not be finalized then. But it would be a major political failure if no agreement were reached in December. Climate change will not wait for drawn-out negotiations, he said.