Instead, Washington challenged its counterparts to meet its "ambitious" offer to impose cuts on farm subsidies in return for wider market access.

"Quite simply for our trading partners to show leadership and meet our ambition," said Neena Moorjani, spokeswoman for chief US negotiator Susan Schwab, when asked about Washington's expectations from counterparts at the Geneva talks.

The meeting, largely to draw up a framework for tearing down tariffs for agriculture and manufactured goods, was aimed at jumpstarting the Doha Round of multilateral trade talks, which has missed a host of deadlines over almost five years of stumbling negotiations.

Late Thursday, the spokesman for EU Trade Commissioner Peter Mandelson said "it is extremely unlikely to have an agreement this weekend" following a meeting of the Group of Six WTO heavyweights -- the EU, Australia, Brazil, India, Japan and the United States.

Moorjani urged Brussels to make a "new EU tariff-cutting offer in agriculture with average cuts north of 60 percent, without big loopholes."

She also called on key emerging markets like Brazil, India, and China to "also do much more to open up their markets in agriculture and in industrial products.

"They should be willing to make real tariff cuts that deliver new trade flows," she said.

Ministers from the EU and several other developed economies as well as the powerful Group of 20 largely developing nations had been pressing Schwab to offer wider cuts in subsidies, which critics say help the United States undercut its competitors.

The Geneva meeting has seen the United States and the European Union throwing challenges and counterchallenges.

EU Trade Commissioner Peter Mandelson had said Thursday that Brussel's position was not entrenched and that the 25-nation EU was willing to approach that of the G20 group of emerging countries.