The UN's top climate change official on Sunday outlined actions for governments to agree to during the Copenhagen climate change conference that opens?in Copenhagen?Monday, saying negotiators now have the clearest signal ever from world leaders to craft solid proposals to implement rapid action.

"Over the next two weeks, governments have to deliver a strong and long-term response to the challenge of climate change," Yvo de Boer, executive secretary of the United Nations Framework Convention on Climate Change (UNFCCC), told a press conference one day ahead of the UN Climate Change Conference.

The UNFCCC is the first international treaty to call for controls on greenhouse gases and serves as a basic framework for the international community to cooperate on climate change.

De Boer spoke of three layers of action that governments must agree to at the conference: fast and effective implementation of immediate action on climate change; ambitious commitments to cut and limit emissions, including start-up funding and a long-term funding commitment; and a long-term shared vision on a low- emissions future for all.

"Never in 17 years of climate negotiations have so many different nations made so many firm pledges together. Almost everyday now, countries announce new targets for fast action to cut emissions. It's simply unprecedented," he said.

De Boer, who is shepherding UN efforts to forge a deal to curb global warming, expressed confidence that there would be many more steps and also a few turning points on the road to a safe climate future. "Copenhagen must be such a turning point," he said.

According to de Boer, developed countries will need to provide fast-track funding on the order of 10 billion U.S. dollars a year through 2012 to enable developing countries to immediately plan and launch low emission growth and adaptation strategies and to build internal capacity.

At the Copenhagen conference, more than 15,000 participants, including delegates from 192 countries, are expected to renew emissions reduction targets set by the Kyoto Protocol, the first commitment period of which expires in 2012, and outline the post-2012 negotiation path.