The two camps have slipped into a familiar pattern of demanding new moves from each other, with the success of this week's high-profile gathering hinging on whether they can leave entrenched positions to find common ground.
The head of the World Trade Organisation, Pascal Lamy, conceded that progress had been modest so far, while British Prime Minister Gordon Brown reminded everyone that the talks were at "the 11th hour."
Indian Commerce Minister Kamal Nath, a leading emerging country representative, offered observers some cause for optimism by praising US attempts to break the deadlock, but he was quick to add that more was required.
"The first thing we must appreciate is that the US is moving," he said. "Up to now there was no movement. The fact movement has started is a good sign."
The United States and the European Union have made opening gambits by offering to reduce trade-distorting assistance to their farmers and they are now waiting for steps by developing nations to open their markets for industrial products.
Nath gave no indication he would give ground on industrial products, but said that he would make a "good offer on services" -- the final component of the talks.
His failure to demonstrate flexibility on industrial products led a spokesman for the US trade delegation, Gretchen Hamel, to question if he was "reading from old talking points."
She added: "If the emerging markets don't contribute it will not be truly be a development round."
The WTO has convened a meeting here of about 30 leading trade negotiators this week with the aim of mapping out a deal to conclude the long-delayed Doha round of global trade talks.
The Doha round began seven years ago with the aim of helping poor countries, but it has been delayed by disputes between developed and developing nations over subsidies and tariffs for farm and industrial products.
The brinkmanship and tit-for-tat demands for new offers between advanced and developing countries fit a pattern that has seen several previous meetings since 2001 collapse without a deal.
"Progress has been modest until now," Lamy conceded in comments to the organisation's 153 members, his spokesman Keith Rockwell said on Thursday.
But Rockwell suggested there had been an "intensification" of talks during and since a ministerial meeting late on Wednesday.
In London, British Prime Minister Gordon Brown warned that the talks were at "the 11th hour" and "a critical moment."
"If we do not succeed in the next few days, then it is very difficult to imagine people returning quickly to the negotiating table to secure the outcome that is needed," he said.
The United States on Wednesday offered to cut its official aid ceiling for its farmers to $US15 billion ($A15.45 billion) a year, $US2 billion ($A2.06 billion) dollars more than a previous offer, in a bid to spur movement at the WTO talks.
The US overture came after an attempt by EU Trade Commissioner Peter Mandelson to jolt the talks into movement on Monday with an announcement that the European Union was now ready to extend tariff cuts on agricultural products to 60 per cent from 54 per cent.
Nath, who arrived late because of a confidence vote against the government in the Indian parliament on Wednesday, had initially called the US offer "wholly inadequate" before praising the "movement" later on Thursday.
The EU offer has been widely dismissed. Brazil described it as "propaganda" and even the EU farm commissioner Mariann Fischer-Boel conceded there was nothing new.
In a sign of French resistance to any more concessions on agriculture, French Trade Minister Anne-Marie Idrac told reporters: "There are no new proposals coming from the European Union."
Amid the bargaining, Indonesia's trade minister sounded a rare note of optimism, saying she had seen "coded signals" indicating that the key players were ready to make new offers to reach a final deal.
"I have to be cautiously optimistic (about progress). There were coded signals -- some evidence was there yesterday, even though they were not putting explicit offers on the table," said Mari Elka Pangestu of a ministerial meeting last night.
