Negotiators at the Paris climate summit have worked through the night on a draft agreement to curb global warming.
There was a widespread expectation that the deal would be signed on Friday - although reports suggest it could be postponed until Saturday.
Delegates have been working on the latest draft since Thursday, in an attempt try to resolve sticking points.
French Foreign Minister Laurent Fabius, who is chairing the summit, said: "I think we will make it."
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.