The European Union and the United States blamed each other on Friday for a stalemate in global trade talks which has put beyond reach an end-April deadline for a key deal on farm and industrial goods.
Trading powers are struggling to bridge the gaps that stand in the way of the World Trade Organisation's (WTO) Doha round which should have been settled in 2004.
Months of cautious diplomacy gave way to what appeared a trans-Atlantic blame game on Friday, even as diplomats were due to discuss ways forward later in the day at the WTO in Geneva.
EU Trade Commissioner Peter Mandelson said he was "looking first to the United States" for "realism" on agriculture.
"What the US is currently demanding is not acceptable to most WTO members - representing half of humanity in fact - and not implementable in Europe," he said in a speech in Helsinki.
The US demands would make farming in Europe impossible to sustain and would hurt poor countries too, he said.
Washington responded in unusually strong terms.
"The (European) Commission is quite adept at speeches, press conferences and finger-pointing," Christin Baker, a spokeswoman for the US Trade Representative's office, told Reuters.
"We just wish they would put the same energy into the needed negotiations to make Doha a success," she said.
The Doha round, which is also seeking to cut barriers to international trade in services, was launched in late 2001 to boost the global economy and lift millions out of poverty.
The talks cannot drag on beyond July or there will not be enough time to finalise all the detail before US presidential powers to negotiate trade deals lapse in 2007, diplomats say.
Mandelson has spent much of his 18 months as Europe's trade chief under pressure to go further with the EU's agriculture offer, especially in cutting import tariffs. But that is stiffly opposed by farming countries in the bloc, especially France.
He has criticised what he says are holes in the US proposals, including plans to cut subsidies paid to farmers.
"While we, since 2003, have been implementing decisions the US has yet to cut a single dollar or dime from its escalating farm spending," Mandelson said.
Leading developing countries, including Brazil and India, also had to make real cuts, not simply reduce ceilings, in the tariffs they impose on industrial goods such as cars and chemicals which are of key interest for the EU, he said.
Aid group Oxfam, which campaigns for the world's poorest countries, said it was disappointed at the "blame tactics."
"Until both trade superpowers get serious about their promises to make this a development round, deadlines will come and go and a deal that helps the poor will remain elusive," said Luis Morago, head of Oxfam International in Brussels.
WTO states were due to meet later on Friday to try to maintain momentum in the talks, which are certain to miss an end-April deadline for a draft deal in farm and industrial goods, two of the main pillars of the round.
States must decide whether to stick to plans for ministers to meet in Geneva around the end of this month. Ministers set the April deadline when they last met in Hong Kong in December.
The announcement this week that the US Trade Representative, Rob Portman, will leave his post to run the US budget has added to concerns that the talks could fail.
In Geneva, a senior US trade official, who spoke to journalists before Mandelson gave his speech, reiterated Washington's long-standing complaint at what it calls the EU's lack of ambition in the farm talks.
"There are a few basic decisions that have to be taken. Are we going to have deep tariff cuts or not," said the official, who declined to be identified.