New Zealand has two days to convince a small number of countries to protect Antarctica's Ross Sea, but whether it will be able to do so remains uncertain.
The Commission for the Conservation of Antarctic Marine Living Resources meeting in Tasmania ends on Friday.
Before 1.3 million square kilometres of the Ross Sea can be protected, 24 countries and the European Union have to approve the creation of a marine reserve.
The New Zealand delegation is optimistic a deal can be reached, however an Antarctic law expert from the University of Tasmania, Dr Julia Jabour, doubts that.
She says if negotiation fails, which would be for a third time, New Zealand needs to go back to the drawing board and reconsider whether marine protected areas are right for Antarctica.
Delegates from other member countries laughed when Radio New Zealand asked if a deal will be possible in two days, saying if it was about science, the deal would be signed off.
Whether the Ross Sea will become a marine reserve should be known by Friday night.