"There is urgency. We cannot maintain forever a trading system that is clearly unbalanced against developing countries," he told an economics conference in Brussels. "Time has come to deliver."

After nearly six years of tough negotiations, the latest round of free-trade talks is reaching a pivotal moment, with June seen by many participants as a make-or-break chance for real progress.

Differences, notably on trade in agricultural products, have blocked progress in the so-called Doha Development Round, launched with great fanfare in the Qatari capital in late 2001.

Raising pressure for a breakthrough in June, the US administration's authority to negotiate international trade deals expires at the end of the month and the Congress is in no rush to renew it.

"My own sense is that concluding these negotiations is not only technically possible, but politically a must," Lamy said.

When leaders of the Group of Eight most powerful countries meet next week in Germany, Lamy said he would give them a three-word message on the trade talks: "just do it."

Ahead of a key ministerial meeting of WTO powerbrokers the European Union, the United States, Brazil and India later this month, Lamy warned against digging into positions that could jeopardize the whole negotiations.

"As we enter the crunch time in this pre-final phase, it is not unusual to see WTO members overplay their contributions and undervalue contributions by others," he said. "This is an old trick."

G4 MEET IN JUNE 'DECISIVE' FOR STALLED TALKS: BRAZIL

Another report from Brasilia adds: A meeting next month of four major WTO players -- the United States, European Union, Brazil and India -- will be "decisive" for stalled WTO world trade talks, Brazilian Foreign Minister Celso Amorim said Thursday.

The four powers have pledged to reach an agreement by the end of the year to unblock the World Trade Organization's Doha Round, which was suspended in July 2006 due to a lack of progress.

Ministers of the so-called Group of Four are to meet June 19 to 22 for crunch WTO trade talks in an as yet undetermined European city.

"I think this meeting will be decisive ... (because) there isn't much time left. And because I see things are moving forward," Amorim said in an interview.

The upcoming G4 meeting will be focused on agriculture, a key sticking point in the round of WTO trade negotiations begun in the Qatari capital in 2001. Developing countries are seeking reductions in farm subsidies by the rich countries, which in turn want greater market access for their industrial products and services.

Ministers of the Group of 20 emerging countries, led by Brazil and India, will hold preparatory talks on June 11 in Geneva, Switzerland, for the critical G4 meeting, Amorim said.

The G20 meeting will provide "a coordination opportunity before this decisive meeting," he said, explaining: "Decisive doesn't mean that everything, down to the last detail, has to be resolved, but it will be a meeting in which we should say if we are leaning toward an agreement or not."

Amorim said the clock was ticking on the Doha Round: "The round should finish by the end of the year or in the first days of next year ... because it will be much more difficult to gain approval (on a trade agreement) in the US Congress in the throes of an election campaign."

Americans go to the polls in November 2008 to elect a successor to President George W. Bush.

That timeframe would require a political evaluation of the numbers and rules of an agreement by the end of July and a definition of the details of its application in September, he said.