Nov. 2 (Bloomberg) -- The United Nations and European Union said the U.S. needs to clarify by how much it intends to reduce its greenhouse-gas emissions in order for an international global-warming agreement to be reached next month in Copenhagen.

Any Copenhagen deal must include the U.S., the biggest historical emitter, which never signed the existing climate- change treaty, the Kyoto Protocol, said UN Framework Convention on Climate Change Executive Secretary Yvo de Boer. He made his comments as delegates from about 180 nations began the last week of preparatory talks in Barcelona before the Copenhagen summit.

“Copenhagen needs to provide clarity,” de Boer told reporters. “I do not think that the international community will accept an instrument that lacks clarity on what the U.S. will do to reduce its emissions.”

U.S. negotiators have yet to present a target in almost two years of talks, and President Barack Obama’s envoys say they’re waiting for Congress to decide on proposed energy and climate- change legislation before they do so. U.S. delegation chief Jonathan Pershing said today that apportioning blame for slow progress “is not the constructive thing to do here.”

“It’s extremely important that we’re a part of this deal,” Pershing said. With more than a month left for Congress to debate proposed laws before the Dec. 7 climate summit starts in Copenhagen, “we think we will have the kind of information that we need to move forward,” he said.

“What we are trying to do is reach an agreement, and that agreement has many, many parts,” Pershing said. “Congress is actively working and seized with this issue.”

Counting on U.S.

Even so, Danish Energy and Climate Change Minister Connie Hedegaard said that other countries have been able to come up with numerical targets even though they too have to seek approval from national parliaments. She said the world during past global conflicts has sought U.S. help.

“We could always count on the U.S. when the world was facing huge challenges,” said Hedegaard, who will chair the Copenhagen talks. “That’s why the Americans should also deliver this time.”

Swedish Environment Minister Andreas Carlgren, speaking for the 27-nation European Union, said he was “urging” the U.S. to contribute and that if other developed countries raise their ambition, the EU will be able to take on a 30 percent reduction target from 1990 levels by 2020 rather than its unilateral pledge of a 20-percent cut.

“We will use this 30 percent as a lever to put pressure on other parties to follow us up,” Carlgren said.

‘Political Essentials’

De Boer said “ambitious mid-term reduction targets” by richer nations are one of four “political essentials” to be included in a deal next month. The others are the actions major developing countries will take to limit their emissions growth, an agreement on climate aid for developing nations and a system of governance to regulate the pact.

Carlgren said that the EU has identified the need for 5 billion to 7 billion euros ($7 billion to $10 billion) a year in 2010, 2011 and 2012 to be provided to developing nations as immediate funding to help them fight the effects of climate change and develop their own emissions reduction strategies.

He declined to quantify the EU’s contribution to that, saying it is dependent on what nations like Japan and the U.S. will pay.

Spain’s state secretary for climate change, Teresa Ribera, said her country will pledge 100 million euros toward that goal. De Boer said $10 billion a year must be agreed in Copenhagen in order to fund “early action.”

To contact the reporter on this story: Alex Morales in Barcelona via amorales2@bloomberg.net.

Last Updated: November 2, 2009 11:05 EST