A 20-nation working group created to sort out differences mainly between European nations and the United States adjourned at 0400 GMT without reaching agreement.

The European Union wants talks to start next year on strengthening the international fight against climate change over the next decade.

It is calling for several informal meetings next year that would include the United States.

But the US representative at the conference, Paula Dobriansky, indicated Washington was only prepared to hold one meeting early in 2005 that would be an "exchange of information" on the environment policies of different countries.

Official talks on measures to follow the Kyoto protocol, which runs until 2012, are to start in November next year.

The United States has refused to ratify the Kyoto protocol on cutting emissions of six key gases, which comes into effect in February, and Dobriansky, the under secretary of state for global affairs, said the European proposal was "premature".

Europe, backed by many leading emerging nations such as China, believe that any post-Kyoto accord would have no meaning without the United States, which is the source of 23 percent of the world's greenhouse gases.

China is next with 13 percent. But with their fast economic growth, Brazil, China and India are becoming major carbon dioxide producers. China has said however that it will not agree to any measures that harms its economic growth.