Some of the world's biggest trading nations piled pressure on the European Union to offer more farm concessions yesterday, saying a four-year push to free up world trade was at risk of collapse without them.

After a latest attempt at a breakthrough failed, the United States and Australia said the EU had to make more sacrifices when cutting the high import tariffs it has used to protect its farmers for decades.

Talks which also included Brazil and India broke up late on Wednesday with no progress towards a key World Trade Organisation (WTO) meeting in less than two months' time.

Warning that the WTO was staring failure in the face, US trade representative Rob Portman said Brussels offered nothing new and time was running out before the meeting in Hong Kong.

"We need to unblock these discussions on agriculture . . . [ and] to go forward the EU needs to come forward with something meaningful on market access," he said. "Unless we see progress soon it's difficult to envisage a successful Hong Kong meeting." Mr Portman said he believed the EU would come back with an improved farm offer market next week.

In December, the WTO's 148 members must approve a blueprint for a trade deal that could boost the world economy and help lift millions of people in developing countries out of poverty.

EU trade commissioner Peter Mandelson, whose room for manoeuvre is limited by the concerns of European farming countries led by France, said he was ready to move on agriculture but insisted talks had to include other areas.

The EU wants progress on industrial goods and services which are a priority for European business. "We want to see further movement on the issue of market access in agriculture, but this cannot be viewed in isolation and WTO members need to understand this," he said.

A breakthrough was needed "in the next fortnight" or else expectations would be scaled down for Hong Kong, Mr Mandelson said.

To avoid that, other countries should not make "hopelessly over-inflated bids", he said in a reference to US proposals for import tariff cuts of up to 90 per cent.

Brazil has ruled out any progress in other areas of the round until there is a breakthrough in agriculture, saying that is where the interests of most developing countries lie.

"The engine remains agriculture and the starter is market access," Brazilian foreign minister Celso Amorim told reporters. "European countries that always put a lot of emphasis on development and poverty must realise this is a crucial moment."

But the French government showed no signs of relenting, insisting it believed Mr Mandelson had offered too much already. "As long as the Commission has not proved it has respected its mandate . . . it's not possible to advance in those talks in Geneva," said European affairs minister Catherine Colonna.

Both the United States and Australia say any new EU offer would have to be pitched between the US 90 per cent cut proposal and a call by the Brazil-led G20 developing country alliance for average tariff cuts of just over 50 per cent. The EU has said it could go over 50 per cent only on its top tariffs and wants a wide number of exceptions from the cuts.