The United States urged Brazil on Wednesday to use its influence with developing nations to ensure that the long-running Doha round of global trade talks do not end in a stalemate.

The appeal came a day after Washington said tough demands made by developing nations could derail the talks, launched nearly six years ago to lift millions out of poverty and boost the global economy by opening up world trade.

"It's time now for Brazil ... to use the significant influence that it has around the world," U.S. Commerce Secretary Carlos Gutierrez said at an event with business leaders in Sao Paulo, Brazil's financial capital.

"Brazil can persuade other advanced developing countries," he added. "To the extent that Brazil shows support and publicly states its support for the WTO agreement, and where it's going, and what they're negotiating this week in Geneva, that will have an impact on other developing economies."

The trade talks, which have hit one road block after another, gained some momentum last month on the basis of papers on agriculture and industry issued by mediators at the World Trade Organization in July.

Gutierrez declined to specify which countries Brazil could persuade to show more flexibility in the talks. But the remarks appeared to be aimed at South Africa, which on behalf of big developing nations like India and Brazil recently said Washington's offer to reduce farm subsidies was insufficient.

For a deal to be politically viable, every WTO member needs to be able to point to some gains to compensate for any sacrifices. Washington wants access to developing country markets for manufactured goods and services in return for cutting its trade-distorting farm subsidies.

"We put a good proposal on the table with regard to subsidies," Gutierrez said. "What we would like to see is a reciprocal response."

Both the United States and the European Union want to continue working on the basis of the texts presented in July. But many developing countries are unhappy with the proposals, while others such as India say they need serious revisions.

"Unless major developing countries now indicate publicly their willingness to negotiate on the basis of the texts that are on the table in Geneva, we face losing a potential deal," Gutierrez said.

Brazil, an agricultural powerhouse with a huge domestic market, has been a major player in the Doha talks from the outset. It has consistently said that a deal will not be possible unless the United States and the EU make significant concessions in agriculture.

Last month, President Luiz Inacio Lula da Silva said on a state visit to Washington that Brazil was "willing to do whatever is necessary" to reach an agreement, raising hopes for a breakthrough in the talks.

"These negotiations are at a critical juncture. This is the time to get it done. And now is the time for countries who really want this to get done to show leadership," Gutierrez said. "The stakes could not be higher, especially for Brazil."