UN climate chief Yvo de Boer on Saturday questioned the will of the developed countries to act to fund climate change.

Climate financing, a issue first mentioned decades ago, has fallen into the category of "far from resolution" in his to-do list, Boer said in Bonn, where negotiators from more than 180 countries gathered for the first round of UN climate change talks since the Copenhagen conference last year.

The outgoing executive secretary of the UN climate change secretariat told Xinhua that he divided climate change issues into three categories: the one near finalization; the one with big difference but perhaps being resolved; and the third, which is "still very far from resolution," that is, the question of climate finance.

The United Nations Framework Convention on Climate Change (UNFCCC), which took effect in 1994 and has been ratified by 194 countries, contains articles of financial support for developing countries to fight climate change.

However, 16 years have elapsed and these pledges are still lying in documents, rather than being converted into actions.

The Copenhagen Accord, put forward at the last minute after marathon talks in late 2009, pledged to offer 10 billion U.S. dollars per year to poor countries in the next three years, and to increase the aid to 100 billion dollars annually by 2020.

"The amount of money was apparently inadequate, compared with the tough mission of fighting climate change and historic responsibilities borne by developed countries," Su Wei, head of the Chinese delegation, said during the April 9-11 Bonn conference.

"What we hope is that these promises can be brought into effect, to meet the urgency of helping developing countries such as the African nations, which are highly vulnerable to climate challenges," he said. "To prevent further damages, the aid packages should be apportioned among wealthy countries as soon as possible."

Spanish chief negotiator Alicia Montalvo said on behalf of the European Union (EU) that the EU would pay 2.4 billion euros (3.2 billion U.S. dollars) per year from 2010 to 2012 in a common climate fund.

However, she did not elaborate on whether the money should come from public finance or private sectors, and which country should get the fund, adding related issues were still under discussion.

Some analysts fear the EU might replace parts of the pledged aid with money from the Clean Development Mechanism (CDM) projects, which they have planned to pay in line with the Kyoto Protocol.

The Copenhagen Accord proposed climate financing, which was a "hopeful" start, but it "does not specify the exact means" to guarantee the targets," said John Ashe, chair of the Ad-Hoc Working Group on Further Commitments for Annex I Parties under the Kyoto Protocol (AWG-KP).

"What is uncertain is where the money is going to come from," he said. "No one knows about it till now."

The Barack Obama administration of the United States had said that the U.S. would offer financial aid for poor countries to fight climate change, but those nations should meet several conditions, such as agreeing to "an international supervision" on emission cuts, which was criticized by many developing countries.

"I still remember, at the first conference of the parties when I worked as secretary, it was industrialized countries that opposed the decision made by majority, because they were afraid of possible decisions on climate finance," Boer said, who is to resign on July 1.

"Affected by international economic crisis, some developed countries tend to stride back in climate issues, as the public's environmental enthusiasm diminished." Su warned. "Some rich nations emphasized their economic recovery while weakening efforts on climate aid and technological assistance for developing countries."

"This backward gesture of rich countries sent strong negative signals to the ongoing climate talks," he told Xinhua.

Some analysts say that climate financing aims to make sure rich countries shoulder their due responsibilities, and the issue is also highly relevant to the future of climate negotiations, both for the dual-track framework of Convention and Kyoto Protocol.

Mexican President Felipe Calderon said earlier that one of the main tasks of the current climate talks was to resolve the financing uncertainties. "If we have a suitable mechanism of economic assistant, the negotiations would be driven back to the right road," he said.