Delegates were told there was a lot to do in the final five days of the event in Glasgow, with negotiators saying they had to work at pace and hold late-night meetings to conclude agreements.
Mr Sharma said talks would have to proceed rapidly in the first few days of the week. “I expect only very few issues to remain open by the evening of Wednesday, November 10, when the near-texts will be presented,” he told the meeting.
Ministers have arrived for the political stage of the negotiations, with Monday seeking a focus on support for poorer countries to cope with climate change.
Talks on finance have already hit problems, with rich countries running late on a promise to deliver $100 billion a year for five years from 2020 to help poorer countries tackle climate change.
Guinea, which represents the G77 group of developing nations, said it was “disappointed that developed countries are unwilling to discuss long-term finance matters,” as did China.
“For the G77 and China, a Cop without a concrete outcome on finance can never be successful,” the conference was told.
Meanwhile, a report by McKinsey and Company has found that more than half of the world’s population could be exposed to drought, floods and dangerous levels of heat by 2050 if global temperatures rise by 2°C above pre-industrial levels. The countries hit hardest will be those that have done the least to cause global warming.
Mr Sharma said finding consensus among almost 200 countries – needed for agreement under the United Nations' climate system – would not be straightforward but progress last week demonstrated a "constructive spirit" among negotiators.
Announcements made last week are not necessarily included in countries' national action plans for this decade, which would leave the world far off target on meeting the internationally agreed goal of trying to limit global warming to 1.5°C to avoid the worst effects of climate change.
Negotiators are trying to hammer out a "cover decision" from Glasgow that will set out how countries will close the gap between the action plans to cut emissions in this decade and what is needed to avoid temperature rises of more than 1.5°C.
Vulnerable countries are pushing for nations to revisit their plans, known as nationally determined contributions, annually to close the gap, but others are pushing back against speeding up the process from its five-year cycle.
"Here in Glasgow we have a unique opportunity to reach a historic outcome and I am committed to bringing countries together to forge an agreement that means we see more action this decade, which helps to keep the 1.5°C temperature limit within reach," Mr Sharma said.
He said there was a need for urgency in the negotiations.
"Last week countries made commitments, which will all help to protect our planet but they must be delivered on and accounted for," he said.