Quashing suggestions from reporters that the talks were about to fail, they said they would try to find ways out of the impasse.

"It's been an emotional roller-coaster today but we will be back tomorrow with strong commitments to continue the negotiations," EU Agriculture Commissioner Mariann Fischer Boel told reporters after an eighth day of talks.

"We are still working," said U.S. Trade Representative Susan Schwab as she left the WTO headquarters for the night.

Progress in the talks ground to a halt on Monday as the United States clashed with China and India over access to their rapidly growing markets, especially in food products.

Negotiators dug in their heels on the details of a "special safeguard mechanism" which would allow poor nations to protect their farmers against any import surges in agricultural products such as rice.

The proposal also pits developing agricultural exporters like Costa Rica, Paraguay and Uruguay against other poor nations.

Separately, nine European Union states -- a third of the total -- demanded better terms for the bloc, adding to concerns that a painstakingly assembled package of compromises that rescued the negotiations last week could disintegrate.

Top trade officials from around 30 key WTO members have been in Geneva since last Monday to try to agree on a range of terms for cutting farm subsidies and tariffs on agricultural and manufactured goods, the core of the WTO's Doha round.

The negotiations for a global deal trade to lower export barriers were launched in 2001, shortly after the September 11 attacks on the United States, in the hope of boosting the world economy and helping poor countries.