More than 100 developing countries have joined forces at world trade talks in Hong Kong to press for greater access to the markets of richer nations.
Developing nations are standing together at the Hong Kong talks
Countries including Brazil, India and several African nations said they would follow a common negotiating line at the World Trade Organization (WTO) summit.
"This is a historic moment, a sort of revolution within the WTO," Brazil's Foreign Minister Celso Amorim said.
The talks have been deadlocked over demands for an end to farm subsidies.
Tensions have been mounting between the US and the European Union, with both sides insisting the other must make concessions for a deal on freeing up global trade to be reached.
EU officials have refused to endorse a 2010 date for ending farm export subsidies, while the US is sticking to its guns on cotton subsidies.
With the 150-member WTO ministerial conference due to end on Sunday, the talks risk ending with no firm deal.
In a joint statement, the developing nations "vowed to intensify their dialogue with a view to ensuring that the negotiations lead to an outcome consistent with the development mandate of the Doha round."
KEY TRADE FLASHPOINTS
Cotton:African cotton producers say huge US subsidies distort trade but the US says it will only agree a deal on cotton as part of wider settlement on agriculture
Bananas: EU preferences to banana producers in former Caribbean colonies were ruled illegal by the WTO and Latin American countries say tariffs are too high
Food Aid: The EU says that all food aid should be given in cash and that US grain shipments to developing countries distort the market. The US believes food aid in kind is vital in famine relief
It was the first time so many developing countries had issued a joint statement within the WTO.
The current conference is due to sign-off the WTO's Doha round framework on the rules of global free trade, which in part addresses the concerns of poorer nations, first launched in the Qatari capital in 2001.
Earlier, South Africa's trade and industry minister Mandisi Mphahlwa said richer countries were demanding too many concessions from developing nations in return for progress on cutting farming subsidies.
"We are not seeing a balance in what we are expected to do in relation to what developed countries are expected to do," the minister said.
But French agriculture minister Dominique Bussereau welcomed the line taken so far by EU negotiators - led by trade commissioner Peter Mandelson - saying France was "extremely pleased with the position of the commission".
French officials had previously accused Mr Mandelson of making too many concessions ahead of the talks.
Trade negotiators remain hopeful that a deal on aid to poorer nations will be made before the end of talks on Sunday.
Ministers and officials are locked in talks to reach broad agreement on a draft declaration covering the current state of negotiations by 0400 GMT on Saturday (noon local time).
It is thought that progress on a package of aid to the world's least developed countries, which would see many given duty-free and tariff-free access to the markets of richer nations, will be included in the draft text, which WTO members expect to be released on Saturday.
Despite signs of a breakthrough in this area, ministers attending the WTO conference have continued to express frustration that little progress has been made on laying the groundwork for an end to agriculture subsidies.
Meanwhile, riot police were out in force at the centre hosting the talks as demonstrators vowed to increase their protests outside the event.