"If a buyer and a seller both feel they have gained from trade, then the agreement is good. But if some need to give up more than others, it will be difficult to reach agreement," Lula said at the closing session of the EU-Brazil summit, the first between the European bloc and the emerging economy within Portugal's six-month EU presidency that started Sunday.

The Brazilian president said he does not plan to leave office without the completion of the Doha trade talks. "I am a man of hope. Agreements are never easy, that is the idea that the poorest nations will have," he said.

World Trade Organization (WTO) talks at the Doha round faltered due to differences over agricultural subsidies in the United States and Europe, which raised the concerns of developing nations, including Brazil, that it would undermine the competitiveness of their produce.

Terming the conclusion of the Doha trade talks as "the greatest challenge that faces the world," Portuguese Prime Minister Jose Socrates said "we must seek more justice and more balance in globalization. Such balance is difficult to achieve."

At the EU-Brazil summit, a deal on a strategic trade alliance was struck, under which leaders of the two sides will meet yearly on climate change and renewable energy issues.