BARCELONA, Spain: As China's actions to curb gas emissions garnered praise at UN climate talks, the United States came under renewed pressure to come up with a plan to cut pollution blamed for hastening global warming.

Delegates at the weeklong talks in Barcelona pressed Monday for Washington to make specific commitments on reducing carbon emissions and contributing to a global climate fund to help poor countries cope with damage caused by climate and Energy Connie Hedegaard said.

Delegates expressed frustration Monday that, after two years of talks on drafting a new pact, the US has been unable to make firm commitments because it is waiting for Congress to enact legislation.

Hedegaard noted that President Barack Obama, cited for raising hopes of a more peaceful and climate friendly world, will receive the Nobel Peace Prize in nearby Norway on December 10 - just after the decisive climate conference gets under way.

"It's very hard to imagine how the American president can receive the Nobel Prize ... and at the same time has sent an empty-handed delegation to Copenhagen," said the Danish minister, who will chair the Dec. 7-18 talks in Copenhagen.

US chief delegate Jonathan Pershing said the US intended to be part of a deal, but would ensure that any deal it signed would be accepted by Congress. "We don't want to be outside an agreement," he said.

He said the US would avoid the mistake of 1997 when its delegation signed onto the Kyoto Protocol, but found unanimous opposition in Congress and was not submitted for ratification.

In Stockholm, Swedish Prime Minister Fredrik Reinfeldt said EU leaders wanted Obama to clarify the US position on climate change this week as they meet in Washington. Reinfeldt - whose country holds the rotating EU presidency - was traveling to Washington along with European Commission President Jose Manuel Barroso and EU foreign policy chief Javier Solana.

In an indirect slap at Washington, Yvo de Boer, head of the UN climate secretariat, said countries like China, India, Mexico, Brazil and South Korea were moving faster on climate change than the wealthy industrial countries.

"China is probably the world leader in limiting greenhouse gas emissions," de Boer said.

China has tried to shift to low-carbon development, but its growth rate is so fast - more than 8 percent a year - that its carbon emissions will continue to climb for decades. Between them, the US and China emit 40 percent of the world's man-produced carbon.

But while the US lagged in developing alternatives to fossil fuels, China became a world leader in the use of wind energy, and President Hu Jintao has said China would generate 15 percent of its energy from renewable sources within a decade. He promised in a speech at the UN General Assembly in September that China also would make "substantial" reductions in its carbon emissions per unit of economic output.

Earlier, de Boer warned that the Copenhagen agreement must have legal force because developing countries do not trust promises from the wealthy nations.

The legal status of the agreement and whether nations will face consequences for failing to meet their commitments are contentious issues in the talks.

"We live in a world of broken promises," de Boer told The Associated Press. Developing countries are concerned the rich countries "will commit to targets and not deliver."

Pershing, in a separate AP interview, said compliance with the agreement in Copenhagen should rest with the domestic laws of each country, which can be very strong.

Countries should register the actions they intend to take to lower the growth rate of carbon emissions, which would then face international inspection. But they would not face punishment for failing to meet their promises, he said.

"I don't think people here are talking about sanctions at all. That's not the discussion," he said.

But many countries want tough compliance measures to be part of any agreement.