Negotiators at the Paris climate summit aim to wrap up a global agreement to curb global warming on Saturday – a day later than expected, hosts France said.
“Things are moving in the right direction,” said French Foreign Minister Laurent Fabius, who is chairing the summit.
But more compromise is needed if an agreement is to be reached, a BBC correspondent at the talks says.
A deal signed in Paris would come into being in 2020.
Mr Fabius told French television that “the atmosphere is good, things are positive” and that a new compromise deal would be presented on Saturday.
Participants at COP21 – as the UN conference is called – have been working on a draft text, prepared by the French presidency, since Wednesday.
This was seen as a significant moment after discussions that began in 2011 about a new global agreement that would stake out a long-term strategy for dealing with climate change.
The French presidency seems to have produced a text with many difficult issues at least partially resolved.
Vulnerable countries appear to have fared well. The document says money to help them get clean energy and to adapt to climate change should be on the table into the 2020s.
The statement says that global temperature rise should be held well below 2C, with the ultimate target set at 1.5C. That is what small island states consider safe.
The document accepts that the combined promises by nations to curb emissions are not nearly enough to meet these targets and there will need to be much greater ambitions from governments in the future.
Some nations are still very unhappy with this text and much more compromise will be needed to bring this historic deal to a close.
On Thursday France presented the latest draft version. At 27 pages long, it was considerably shorter than previous versions.
It says that temperature rises must be kept “well below 2C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5C”.
The number of square brackets, indicating significant disagreement, had been reduced to around 50, a major improvement on Saturday when they ran to more than 900.
But there are still considerable difficulties about issues including climate finance and the question of demarcation between developed and developing countries.
Called “differentiation”, richer nations want emerging economies should take on more of the burden of cutting emissions and providing finance to the very poor nations hit by the impacts of rising temperatures.
The richer countries were also insisting on a single system of verification of promises for all countries.
“We feel that when parties have committed themselves to a national target that reflects their ambitions and abilities, they must be ready to tell the global community what type of progress is being made,” said Elina Bardram, the EU’s chief negotiator told reporters.
“We need to have accounting standards and principles that are common to all – otherwise you are simply comparing apples with pears.”
COP 21 – the 21st session of the Conference of the Parties – sees more than 190 nations gather in Paris to discuss a possible new global agreement on climate change, aimed at reducing greenhouse gas emissions to avoid the threat of dangerous warming due to human activities.
“The really tough issues in the negotiation are still very much sitting there,” warned New Zealand’s Climate Change Ambassador, Jo Tyndall.
It had been hoped a deal could be reached Friday but organisers said they wanted to give delegates more time for consultations rather than stick to the original schedule.
Some campaigners were not happy with Thursday’s draft, saying it denied “climate justice”.
“Rich countries have a responsibility to ensure a fair global deal for everyone, not just themselves, and as we move into these final hours of negotiations poorer countries must not settle for anything less,” said Adriano Campolina, from ActionAid.
But Helen Szoke from Oxfam called it an “encouraging development”.
“The draft has affirmed the need to set quantified funding goals for both climate change mitigation and adaptation for the years after 2020,” she said.