Fresh from a White House meeting Tuesday with German Chancellor Angela Merkel, who also made a heart-felt plea for a climate protocol in a speech to US lawmakers, US President Barack Obama held talks with European Union leaders to assure them his administration supported clinching a new treaty in Copenhagen in December.

The EU-US summit goes into its second day Wednesday for talks with US Energy Secretary Steven Chu, after the Europeans pressed Washington to take action on climate change and Obama stood shoulder to shoulder with his European allies in pressing to redouble efforts to combat global warming.

"All of us agreed that it is imperative for us to redouble our efforts in the weeks between now and the Copenhagen meeting to assure that we create a framework for progress in dealing with (a) potential ecological disaster," Obama said after talks with European Commission chief Jose Manuel Barroso, Swedish Prime Minister Fredrik Reinfeldt and EU foreign policy chief Javier Solana.

Merkel, in a rare speech to a joint session of Congress, compared the battle over climate change to the struggle to bring down the Berlin Wall two decades ago next week.

She also backed Western calls for emerging nations to do more. "I'm convinced that once we in Europe and America show ourselves ready to adopt binding agreements, we will also be able to persuade China and India to join in," she said.

But even as she and Obama stressed the need to solidify a framework agreement at Copenhagen, US Republican lawmakers boycotted a committee meeting on an Obama-backed bill to set the first US requirements on curbing carbon emissions blamed for global warming.

Asked what impact Merkel's speech might have on the US debate, Senator James Inhofe, the top Republican on the committee looking at the climate legislation, said: "None whatsoever."

Barroso, who praised Obama for having "changed the climate on climate negotiations," said he was "worried by the lack of progress in negotiations" ahead of the December 7-18 climate meeting that aims to seal a treaty to succeed the Kyoto Protocol before it expires in 2012.

"Of course we are not going to have a full-fledged binding treaty, Kyoto-type, by Copenhagen," Barroso told reporters. "This is obvious. There is no time for that."

An international meeting next year in Mexico could be used to finalize a treaty, but Barroso said Copenhagen needed to come up with the framework of the deal, and that the world's largest economy in particular should take a lead role.

"What we are asking is the United States to show leadership in this, such an important issue," Barroso said.

After meeting with Obama, he said he was "more confident now" about Washington's commitment, but also warned against protracted negotiations akin to the stalled Doha round of trade liberalization talks.

Reinfeldt, whose country currently holds the rotating EU presidency, said the United States should at least agree on targets for cutting emissions and on financing for developing nations.

"I said that we need to have a clear commitment on targets and on financing coming from the United States," he told AFP after talks with key senators.

"We can understand if it's not possible to have everything in place exactly now. But we want a full agreement in Copenhagen and we are able to work through details in the months that come after Copenhagen."

Reinfeldt spoke as pre-summit negotiations were underway in Barcelona, Spain, where divisions again ran deep between key developed nations and emerging economies.

An EU summit last week agreed that developing nations will need 146 billion dollars (100 billion euros) per year by 2020 to tackle climate change, but failed to nail down how much aid it would provide.

The US role in Copenhagen is overshadowed by the debate in Congress.

The House of Representatives in June narrowly passed the plan to curb carbon emissions by 17 percent by 2020 but the bill -- already criticized by other developed nations as not ambitious enough -- is bogged down in the Senate, where a slightly more ambitious version calls for a 20 percent cut by 2020.

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.