Countries are to be presented with the final draft of an international climate change deal as two weeks of tough negotiations draw to an end.
Ministers from more than 190 countries have been engaged in "shuttle diplomacy" and diplomatic wrangling to find common ground for the agreement being hammered out in Paris, which aims to limit global temperature rises to avoid dangerous climate change.
A final draft was agreed at around 6.45am local time on Saturday, according to United Nations officials, and has been sent to translators and legal teams before being presented to countries at a meeting at 11.30am (10.30am GMT).
French President Francois Hollande will return to the conference, where he welcomed around 150 world leaders almost two weeks ago amid huge fanfare, for the meeting to add weight to the final push to secure the deal.
If adopted at the talks, which have overrun their official Friday deadline, the deal will be the world's first comprehensive climate agreement with all countries taking action to tackle the problem.
It is thought negotiators are generally upbeat about the agreement, which will set long-term targets for curbing global warming and provide finance for poor countries to develop cleanly and cope with the impacts of rising temperatures.
The final agreement could include references to making efforts to keep temperature rises to no more than 1.5C above pre-industrial levels - a key ask of the most vulnerable countries who fear greater warming could threaten their very survival - as many countries were thought to be "comfortable" with the idea.
As the talks overran, key sticking points had emerged between countries, including the level of ambition of greenhouse gas emissions cuts and preventing rising temperatures.
Finance for poor countries to deal with climate change, and the different responsibilities of developed and developing countries to tackle and pay for it, were also key.
And the issue of "loss and damage" - the recognition that some of the most vulnerable countries need support to cope with irreversible impacts such as inundation of their land from rising sea levels - has been hugely difficult at the talks.
Despite the thorny issues, the atmosphere at the talks has generally been described as very good - and much better than at previous UN climate talks - with countries keen to get a deal.