In the Copenhagen Accord last December, developed countries had pledged to offer 10 billion U.S. dollars per year to help poor countries combat climate change in the next three years, known as "the fast-track approach", and to boost the aid to 100 billion dollars annually by 2020.

Some delegates from developing countries said the "fast track" was not fast at all since there were still no clear picture on how to raise and allocate the urgently-needed fund. But rich countries complained that the poor ones always want more money, which has exceeded the limits of reality.

Dessima Williams, chair of the Alliance of Small Island States, told reporters that she saw a deadlock since Copenhagen Accord about rich nations' emissions cut pledges.

"We cannot anticipate any major shift from what we had in Copenhagen, which was a 12 to 18 percent reduction when the IPCC ( Intergovernmental Panel on Climate Change) called for 25 to 40 percent. We are far from that in the aggregate figures," she said.

Scientists estimated that nations'current voluntary emissions cut pledges in Copenhagen Accord could lead to a global warming of 3.5 to 4.0 degrees Celsius, far above the 2 degree "red line" for the earth.

Moreover, the United States, one of the main emitters and players in climate talks, remained unclear on whether it would keep the promises of reduction, as the U.S. Senate decided to abandon a domestic climate bill this year.

"It has been taken as a signal by some that the process should be slowed or we should wait for the U.S.," Williams said.

Jonathan Pershing, the U.S. deputy special climate envoy, responded in the meeting that the Obama administration would be committed to reducing its carbon emissions 17 percent from 2005 levels by 2020, and Obama would not give up on passing a sweeping climate and energy bill.

But some countries said the lack of climate legislation in the United States would inevitably cast a shadow on climate talks as parties feared that the country would repeat what it did to the Kyoto Protocol in 1990s -- the administration openly supported the protocol but received a "no" answer from the Senate.