The Europeans see it as essential to get the United States and major emerging economies such as China and India on board on a new agreement on reducing greenhouse gases that would follow the Kyoto pact in 2013.

The United States, which has never ratified Kyoto much to the chagrin of its backers, has not shown interest in new negotiations.

Emerging industrial giants may be hesitant to sign on to international efforts to curb greenhouse gas emissions, for fear they could throw the brakes on their own economic growth.

Environment ministers from around the globe will take up the debate December 15-17 at the 10th annual UN climate change conference under way in Argentina's capital.

The United States sees it as "premature" to take up the post-2012 issue, arguing it will take its own approach to combat rising global temperatures and use new technologies to do so.

Yvo de Boer, head of delegation for the rotating EU presidency, told reporters Tuesday "there are still differences of views."

"A vast majority of parties agree that the seminars (informal meetings under way) should focus on the future," he said, noting: "I'm quite optimistic" about a final compromise.

The 1997 Kyoto accord legally commits 39 industrial nations and territories to trim their output of six greenhouse gases -- especially carbon dioxide -- by at least 5.2 percent by 2012, compared with 1990 levels.

Russia's ratification in November gave the protocol the final stamp of approval needed to go into force on February 16.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.