The Presidents of Brazil and the United States are determined to push stalled global trade talks and Washington hopes to see some progress in coming weeks, the U.S. ambassador to Brazil said on Monday.

Brazil and the United States are part of a core group of negotiators, including India and the European Union, which failed to reach a framework agreement within the World Trade Organization's Doha round of talks.

The presidents are very, very much focused on getting a positive response, said Ambassador Clifford Sobel, who accompanied high-level bilateral talks in Brazil this month centering on the Doha round.

It's complicated, but we've not given up, and perhaps with leadership like President (George W.) Bush and President (Luiz Inacio) Lula (da Silva) ... we can still be successful, Sobel told a meeting of the Rio de Janeiro Industry Federation.

WTO talks resume this week in Geneva ahead of a ministerial meeting, possibly in September. WTO mediators last week proposed last-ditch compromises to overcome impasses over agriculture and industrial goods.

Opening up to a larger group of countries in Geneva may be the kind of catalyst needed for a breakthrough, Sobel said.

Brazil said the compromise proposal leaned too heavily in favor of rich countries.

Sobel said that other countries needed to be flexible and that developing countries had the most to gain from a successful pact.

The round was launched in 2001 to boost the global economy and help developing countries use trade to fight poverty.