Negotiators in Paris are again expected to work through the night in an effort to secure a new global climate deal.
The French president of the meeting said the “conditions were never better” for a strong and ambitious agreement.
Laurent Fabius said he was confident of presenting the final draft early on Saturday morning.
The document will be assessed by participants before a final plenary meeting of all the parties to approve the deal.
Despite insisting throughout the conference that the deal would be done by Friday evening, Laurent Fabius had to concede to the reality that critical issues remained and extra time would be needed.
Observers were concerned about the slippage, saying there were some concerns now that the time for compromises would run short.
“There has to be a take it or leave it text on Saturday,” said Dr Diarmuid Torney from Dublin City University.
“With the length of time needed for processing and revising the document, whatever is released will be France’s pitch for the final agreement,” he told BBC News.
