The COP28 presidency is expected to release a new draft text of what would be a hoped-for final deal from the summit.
At that point, the negotiations kick into high-stress mode, with countries wanting language to "phase out" fossil fuels facing off against those who see them as an economic lifeline.
For many countries resisting a fossil fuel mention, the final deal should focus instead on reducing climate pollution, rather than on the fuels that are causing it.
Time for an agreement is running short, with the summit scheduled to end on Tuesday. And stakes are high - with the talks expected to continue well into Monday night.
Any mention of fossil fuels would mark the first time countries have directly addressed them in 30 years of U.N. climate talks - something that the summit host, the United Arab Emirates, would hail as a success.
For opponents, such as OPEC members Saudi Arabia and Iraq, any such move would be a hard sell at home.
