Ministers from about 35 key nations are meeting in Geneva this week to break seven-year deadlock over a new global trade deal.
But so far, emerging markets have expressed frustration at the lack of concrete moves from big developed parties such as the United States and the European Union.
An attempt by EU Trade Commissioner Peter Mandelson to jolt the talks into movement on Monday with a proposal to extend EU tariff cuts on agricultural products to 60 percent from 54 percent, looked like a damp squib on Tuesday.
Even Mandelson's fellow EU commissioner Mariann Fischer-Boel said the offer was "nothing new", and Brazil dismissed it as "propaganda".
A central point from the EU standpoint is an offer of concessions by emerging countries in such fields as industrial protection to compensate for any cuts in support for EU farmers.
But Paraguay Foreign Minister Ruben Ramirez Lezcano said on Tuesday that negotiations could not advance without substantial proposals from the United States a