Negotiators from almost 200 countries are making a last-minute effort to resolve differences on the rules that will govern the 2015 Paris climate accord.
Diplomats and ministers worked through the night to present fresh drafts on the rulebook and other issues Thursday to the chair of the U.N. climate talks in Poland.
A Polish diplomat overseeing the two-week meeting is expected to merge the drafts and present them to delegates in the afternoon.
German negotiator Karsten Sach told reporters that a key test of whether the talks will conclude successfully Friday.
Other issues include financial support for poor countries and how to acknowledge of a key scientific report on keeping warming at 1.5 degrees Celsius (2.7. Fahrenheit) that major oil producers called alarmist.