One year ago the talks suffered another setback at a meeting in Potsdam, Germany, that showed deep divisions remained between India and Brazil and the United States and the EU over how to reform agriculture and manufactured goods trade.
This week's talks are overshadowed by uncertainty over whether the U.S. negotiators can deliver on any deal reached in the waning months of the Bush administration.
U.S. lawmakers recently approved new farm legislation that could greatly boost farm subsidies if prices fall.
Also, the White House's authority to submit trade pacts to Congress for a straight up-or-down vote without any amendments expired over one year ago.
Developing countries are pushing in the talks for deep cuts in rich country farm subsidy and tariffs, which they believe have hurt their farmers for years.
But the United States and the EU say they can only sell a deal that gives them meaningful new export opportunities and developing countries have been resisting that.
"Big emerging countries like Brazil, India and China should not hide behind the label of a developing country," said Michael Glos, economy minister of Europe's biggest economy, Germany.
"For me, it is essential that the big emerging countries take on their responsibility for the multilateral trading system. They, too, must provide real improved access to markets. Greater market access must not be a one-way street," he said in a contribution to Monday's Financial Times Deutschland.
The main pressure on Brussels at this point in the negotiations is to limit the number of "sensitive" products it shields from deep tariffs cuts.
The United States has high tariffs for farm products such as sugar, dairy products, tobacco and meat, but is mainly being asked to dramatically cut its current WTO spending ceiling for trade-distorting farm subsidies.
