GENEVA — The European Union began crucial global trade talks Monday with an offer of reducing its farm tariffs by 60 percent — the highest figure it has yet offered — in a challenge to developing countries to make concessions.

The offer from the European trade commissioner, Peter Mandelson, was intended to ignite the stalled Doha trade round, which began seven years ago.

Until now, Europe has offered a maximum of 54 percent tariff reductions, but Mr. Mandelson’s spokesman, Peter Power, said the higher figure could be achieved by including a range of tropical products.

It remained unclear whether Europe’s intervention would break the overall stalemate, because the basic shape of the European offer remained the same.

The talks this week in Geneva are seen as the last chance to achieve a global deal to liberalize trade in the near future. With a presidential election looming in the United States and Europe scheduled to change its trade negotiator next year, a breakthrough this week is seen as essential to any hopes of a swift agreement.

Europe and the United States want developing countries like Brazil and China to open up more of their markets for industrial goods and services in exchange for concessions on agriculture. Washington has said that it is willing to cut farm subsidies.

But developing countries remain dissatisfied with the agricultural concessions offered so far by Europe and United States.

“We’ve decided to help the negotiations this week get off to a strong start by raising the average cut in our agricultural tariff,” Mr. Mandelson said, according to The Associated Press. “That is a very considerable improvement on our own part, but of course it’s light years away from any effort we’ve previously made in a trade round.”

Mr. Power added that the offer had failed to produce any response from the developing nations. “We have shown leadership throughout these negotiations,” he said, “and we are kicking this meeting off by showing our continued willingness to do so. The disappointing reality is that we are not seeing any return so far.”

Earlier, the United States trade representative, Susan C. Schwab, gave her first public reaction to comments by the Brazilian foreign minister, Celso Amorim, that compared what he called rich countries’ deception in commerce talks to tactics used by the Nazi propaganda chief, Joseph Goebbels.

“This is not the time and not the week for falling back on tired rhetoric,” Ms. Schwab said. “Rhetoric designed to perpetuate old divisions or create new ones.”

Meanwhile, there was no sign of a breakthrough in a dispute over Europe’s banana tariffs, which have threatened to derail the talks. Latin American nations are at odds over the proposed new regime with Europe’s former colonies, which have traditionally had preferential treatment.