World trade negotiations potentially worth billions of dollars to New Zealand exporters face make-or-break talks this week.
The head of the World Trade Organisation says the 10-year Doha round could collapse if a breakthrough is not made.
The 153 countries reported back to WTO director-general Pascal Lamy late last week - without bridging key differences.
Mr Lamy has now given them until Friday to resurrect the talks.
Differences between the United States and the European Union and so-called developing countries are hindering progress.
These relate to the removal of tariffs on industrial goods exports from the US and EU to China and other developing countries.
New Zealand Trade Minister Tim Groser puts the chances of a breakthrough at just 20%.
It is unclear what will happen if a breakthrough is not reached by the end of the week. Some reports say a smaller deal could be done, leaving more contentious issues until later.