|Delegates from developed and developing countries have not seen eye-to-eye at the UN climate conference [Reuters]
Negotiators are locked in intense last-minute talks at the UN climate summit in Cancun, Mexico, bargaining intensely over draft accords and seeking small but essential steps to stem global warming.
Participants saw a growing consensus on how to set up a "climate fund," which would start making use of the hundreds of billions of dollars of aid pledged for developing countries worst affected by rising temperatures.
The fund seeks to provide up to $100bn a year for developing countries threatened by altered weather patterns, and give them the technology to leapfrog old petroleum-based economic development in favour of clean energy.
But delegates saw a number of other stumbling blocks - on how to verify countries' pledges, on the role of markets in climate aid and, most prominently, on the future status of the landmark Kyoto Protocol.
"This is a crucial day, not only for the process but for the climate," Joke Schauvliege, a leader of the European Union delegation, said on Friday.
In a late-night session on Thursday, negotiating groups reported they had settled some disputed wording and clauses, but other complicated issues remained to be sorted out.
Patricia Espinosa, Mexico's foreign minister and the conference chair, said: "We have very limited time."
Participants said it was increasingly likely that the two-week conference of more than 190 nations would run past its scheduled closing time late on Friday
Al Jazeera's Lucia Newman, reporting from Cancun, said: "We are hearing from delegates that it may be extended for another 24 hours."
One dispute, related to pledges by industrial and developing countries to rein in emissions of heat-trapping gases, appeared deadlocked.
Despite the reported progress on several fronts, Connie Hedegaard, the EU's top climate official, said countries were withholding approval on all issues until everything was ready.
"Everything is still being negotiated until we have the full package," she told reporters. "Nothing is cut in stone."
The limited agenda of secondary issues the UN conference had set for itself was proving tougher than expected.
It was clear in the final hours of the talks that delegates were looking for creative language to finesse irreconcilable views and buy another year until the next major congress in Durban, South Africa.
Erik Solheim, the Norwegian environment minister and a veteran of many diplomatic battles, urged negotiators to embrace flexibility.
"If you want to pick fights in this audience, it's very easy to do it. What we need is a spirit of compromise," he said to a round of applause.
Among the issues in a set of draft accords are compensation for halting the destruction of forests for timber or for clearing agricultural land.
China and the US were bickering over rules for countries to report actions curbing greenhouse gases and submit them to international scrutiny.
Even the forestry programme, which had been touted as one of the easiest potential deals at Cancun, met last-minute hurdles over how to make sure that the rights of indigenous communities are safeguarded.
From Kyoto to Copenhagen
Off the agenda was any proposal for industrial countries to ramp up the modest pledges they had made since the last annual meeting in Copenhagen for reducing greenhouse gas emissions that are causing a measurable rise in the Earth's average temperature.
That summit failed to produce a hoped-for overarching climate pact and instead concluded with a three-page political document, the Copenhagen Accord.
The 27-nation EU wants language specifying that emissions pledges over the last year fall short of what scientists say is necessary to keep the Earth from overheating to dangerous levels.
Hedegaard said that the agreement should reflect "that the Copenhagen pledges are not the end of the story, they're the beginning".
A key issue of contention was whether to make the post-Copenhagen national emissions pledges legally binding, and in what kind of document.
The answer to those questions would determine the fate of the Kyoto Protocol, the 1997 document that set reductions targets for 37 wealthy countries and which expires in 2012.
The US rejected Kyoto - the only industrialised country to do so - because it did not require fast-growing economies such as China and India to limit their emissions.
Developing countries attach huge importance to Kyoto as their only legal weapon against the wealthy countries, whom they blame for creating the global warming problem by dumping greenhouse gases into the air for the past 200 years.
'Ecocide and genocide'
Evo Morales, the Bolivian president, warned against letting the Kyoto pact die in a fiery 20-minute speech on Thursday to the 15,000 delegates, activists and journalists.
"If, from here, we send the Kyoto Protocol to the rubbish bin we are responsible for ecocide and genocide," he said.
Japan reiterated its opposition to extending the protocol with new targets unless all the major emitting countries, including the US, China, India and other economic powerhouses, accept comparable binding targets.
On the sidelines of the conference, countries, businesses and international agencies struck deals or announced projects to show they would take action against climate change independently of the talks.
Robert Zoellick, the World Bank President, announced the creation of a $100m fund to help countries create carbon-trading markets.
"Regardless of what happens in the negotiations, we shouldn't be waiting. We should be doing practical things on the ground," Zoellick said.