Just when you thought the Doha Round of global free trade talks was dead and buried, World Trade Organisation Director General Pascal Lamy says he is ready to call ministers back to Geneva to close a deal.

"The reasons why we must conclude the Round are becoming more critical by the day as the economic and financial outlook continues to deteriorate," Mr Lamy said yesterday in a speech to the United Nations.

His latest call to arms follows meetings in Geneva last week between key officials and negotiators in an effort to begin moving the Doha Round of global trade talks forward, following their collapse in late July.

And such is the momentum building that US Department of Agriculture chief economist, Joe Glauber, has confirmed that many trade officials are headed back to Geneva this week to see if there is some basis that they can further progress the talks.

Mr Glauber, who is the main agricultural negotiator for the US, says the sticky issues of the limited supplies of food commodities and current high prices of food were main factors in the collapse of the talks in July.

"Obviously if you're trying to convince countries that are concerned about food security but recognise that there is value to reducing tariffs so they can import in times when supplies are tight," Mr Glauber said.

"At the same point you can't tell them those supplies might not be there because someone has decided to increase their effective taxes or whatever at the border."

But Mr Lamy said yesterday he was "convinced that a deal is still possible".

"I still believe that with yet another push we could still reach our target," he said.

Mr Lamy said officials had progressed negotiations and have closed many of the gaps between the key countries.

But agricultural tariffs and subsidies remain a sticking point, even though a deal was nearly reached in July.

"It would also be fair to say that even after agriculture and industry modalities are established, there would remain important work to translate these into detailed country-specific schedules of commitments," Mr Lamy said.

"There is now far too much on the table, particularly for developing countries, to give up on these negotiations.

"And while I believe there is scope for renewed engagement over the coming weeks, it is clear that we are coping with a fragile situation."