Countries negotiating a new global trade pact showed no willingness to budge from their fixed positions in past days, says the chairman of agriculture talks at the World Trade Organisation, Crawford Falconer.
Mr Falconer has been holding talks on farming issues that were meant to clear the way for a breakthrough in the WTO's seven-year-old Doha round.
WTO Director-General Pascal Lamy has held off setting a date for trade ministers to come to Geneva to seek agreement, in order to assess advances shown among diplomats this week.
Mr Lamy will meet key WTO ambassadors on Sunday to take stock of the talks, and Mr Falconer's findings will be factored into that assessment.
If ministers come to Geneva, they will seek to reach an outline agreement on the core areas of the Doha talks - cuts in agricultural subsidies and in farm and industry tariffs.
A meeting of ministers in July came close to a deal but ultimately collapsed over disagreements about a safeguard to help subsistence farmers withstand a surge in imports.
That remains unresolved, as do several other contentious issues, such as US subsidies for cotton and proposals to help mainly rich countries shield politically sensitive products from tariff cuts.
Before ministers can meet, Falconer and his counterpart for industrial goods, Swiss ambassador Luzius Wasescha, will need to reflect the latest compromises in the talks in revised negotiating texts that would serve as a blueprint for ministers.
Estimates of the benefits of the Doha round to open up world trade vary widely. One study last week by the International Food Policy Research Institute found that more than $US1 trillion of trade was at risk if a deal did not go through.
New Zealand's Prime Minister John Key has called for further moves to liberalise trade and resolve the stalled Doha trade talks, in a speech at the Asia-Pacific summit in Peru.