COPENHAGEN (Reuters) -- UN Secretary-General Ban Ki-moon and the Danish hosts have urged countries to compromise to salvage agreement on a new UN pact aimed at averting dangerous climate change.
Ministers were struggling to break deadlock in global climate talks in Copenhagen, three days before world leaders were due to seal an accord.
"In these very hours we are balancing between success and failure," said the Danish president of the two-week meeting, Connie Hedegaard, at the opening of the high-level phase of the talks.
"Success is within reach. But...I must also warn you: We can fail."
Organizers of the talks had said environment ministers would work deep into the night to narrow wide differences, saying the bulk of the work must be complete before some 115 leaders formally join the meeting on December 17.
"Three years of effort have come down to three days of action," Ban said. "Let us not falter in the home stretch. No one will get everything they want in this negotiation."
Later, the White House said U.S. President Barack Obama is confident of securing a climate-change deal at the summit.
"The president believes that we can get...an operational agreement that makes sense in Copenhagen, over the next few days," White House spokesman Robert Gibbs told a briefing.
After a suspension of several hours the previous day, talks were stalled over disputes about the level of emissions cuts by rich countries and a long-term global target to curb a rise in global temperatures that could trigger rising sea levels, floods, and drought.
Draft texts dated December 15 showed that national negotiators had stripped out figures for long-term global goals and rich-country emissions cuts by 2020 from last week's UN texts. The numbers could be reinserted if agreement is reached.
Major U.S. businesses including Duke Energy, Microsoft, and Dow Chemical called for tough U.S. emissions cuts that would mobilize a shift to a greener economy.
"There's a great deal yet to do, the parties are quite far apart on a fair number of issues," said Todd Stern, U.S. special envoy for climate change, adding he did not expect any change in U.S. targets for emission curbs during the talks.
Ministers were expected to work late into the night. "It is not their [leaders'] role to negotiate text," said Brazil's climate change ambassador, Sergio Serra, emphasizing that most work must be done by December 17.
The Copenhagen talks, which Ban described as among the most complex and ambitious ever to be undertaken by the world community, have stumbled over a long-running rich-poor rift on addressing the threat of climate change.
A "BASIC" group of China, India, Brazil, and South Africa was "coordinating positions almost on an hourly basis", India's environment minister, Jairam Ramesh, said, reinforcing the entrenched rich-poor positions.
South African Environment Minister Buyelwa Sonjica, speaking for the group, said rich-country pledges for emissions cuts were "less than ambitious and...inconsistent with the science."
Developing nations also want the industrialized world to pay poorer countries to prepare for and slow climate change.
Japan would offer $10 billion in aid over three years to 2012 to help developing countries fight global warming, including steps to protect biodiversity, a Japanese newspaper said today. The European Union has offered a similar sum.
French President Nicolas Sarkozy said in Paris that he hoped U.S. President Barack Obama supported "fast start" aid for developing countries. "President Obama often speaks about his links with Africa, it is time to show it," he said.
British Energy and Climate minister Ed Miliband, chair with Ghana of a group looking at the funding promises, said, "There are clearly still issues about the scale of public finance and what can be committed to at this point."
He pointed to wide divergence in positions.
"The G77 [group of developing nations] wants 0.5 percent of GDP -- I don't think we're going to achieve that. The European Union has its figures, 22-50 billion euros in 2020."