After meeting here with French Prime Minister Dominique de Villepin, Mandelson repeated that he did not believe an agreement on a negotiating framework could be reached before an April 30 deadline.

"I don't think that we will make the breakthrough at the end of this month that we wanted but I remain committed to negotiating effectively, intensively to achieve the deal that we are looking for by this summer," he said.

"But we will only have that deal by this summer or at anytime if we see not just progress in agriculture but profound movement in the other sectors of the negotiations: industrial goods, services as well as strengthening our world trade rules."

Referring to the French premier, Mandelson added: "He believes as I believe that Europe is making a fair, generous offer to bring about this success. We have to see a fair and balanced return.

"We need firmer, stronger offers from our negotiating partners to achieve that balance that is indispensable to us to complete these negotiations successfully."

Key differences on reducing customs duties and other barriers to commerce remain unresolved, and senior diplomats representing the 149 members of the World Trade Organisation were to gather Monday to review the impasse, the WTO said on Friday.

The deadline of April 30 was part of a loose accord put together hurriedly at a December WTO conference in Hong Kong.

De Villepin said Monday in a statement that he had expressed "concern over the lack of progress on opening industrial markets and services in large emerging countries which are decisive for French and European companies".

The French premier added that he would remain "highly vigilant regarding agricultural questions and strict respect for the (EU) Common Agricultural Policy as it was reformed in 2003".

On Friday, finance ministers from 24 developing countries voiced concern in Washington that WTO negotiations launched in late 2001 in the Qatari capital Doha to lift barriers to world trade were now "at risk."