GENEVA (AFP) ― Negotiators have failed to fix a deal for a crunch summit next week, casting a shadow over efforts to revive stalled talks on slashing barriers to global commerce, the head of the WTO said Tuesday.

“The reality is that we have proved that we can’t cross the final yard here in Geneva. The process here is over,” World Trade Organization chief Roberto Azevedo told reporters after a marathon session ended without a final accord.

Underlining that trade diplomats got achingly close before positions hardened over recent days, Azevedo threw the ball into the court of trade ministers who will meet from Dec. 3-6 at a WTO summit on the Indonesian island of Bali.

“If we are to get this deal over the line, we will need political engagement and political will. Ministers will have to decide what kind of future they want to see both for the issues that are on the table today and for the WTO,” he added.

The Bali summit is seen as perhaps the last chance to revive the WTO’s “Doha Round” talks, launched in 2001 at a summit in Qatar, and on-off from the outset.

U.S. trade ambassador Michael Punke gave a bleak assessment Tuesday.

“A once-in-a-generation opportunity may have slipped our grasp,” he told fellow negotiators.

Mexican trade envoy Fernando de Mateo struck a different tone, telling reporters: “Hope is the last thing that you lose. We‘re so near that it’s not impossible.”

And in a statement, European Union trade chief Karel De Gucht said: “As we are so close to the shared objective, we should not give up.”

The Doha Round aims to produce a wide-ranging accord to open markets and remove trade barriers, with a key goal being to harness international commerce to develop poorer economies.

By some estimates, Azevedo noted, it could provide a $1 trillion boost to global commerce.

The Doha Round has stalled repeatedly as rich countries, emerging powers and the world‘s poorest nations spar over the give and take needed to craft a deal.

Azevedo, Brazil’s former trade envoy who took the WTO helm in September, was set to spend coming days telephoning ministers to try to close gaps.

“There are quite a few benefits that we are all going to let go if we don’t conclude the deal, (including) the opportunity for further deals,” he warned.

Earlier Tuesday, he briefed diplomats from the WTO’s 159 member economies on the state of play.

They pored over a 53-page draft accord which still contained an array of bracketed options ― standard diplomatic practice ― which over recent weeks were cut from a thousand to 65.

“We should not give up now. We should not say here in Geneva that it‘s a failure,” said Morocco’s trade envoy Omar Hilale.

“We‘re not going to declare the Bali conference over before we’ve even started it,” he told reporters.

“Bali provides an opportunity for ministers to discuss the complex issues and find a way forward,” agreed South Africa‘s Faizel Ismail.

Negotiators had long ruled out the chances of major progress in the Doha Round in Bali and instead worked on lower-level thematic accords to be fed into a wider package later.

One covers “trade facilitation,” which involves simplifying customs procedures to ease commerce.

Divisions there center on the time-lag developing countries would get to fall into line, plus the support they would get from donors to do so.

Another division is over “food security,” pushed by India, under which developing countries want the right to subsidize grain stockpiles to help low-income farmers and consumers ― stocks that critics warn could end up on the open market, skewing trade.

WTO rules require deals to be unanimous, and the impasse has seen many members shift focus to negotiating deals such as the Trans-Pacific Partnership or a U.S.-EU accord.

Such regional deals tend to involve richer countries, sidelining the poorest nations ― who at least have a say within the WTO, which seeks to create global rules.

Azevedo warned that failure in Bali would not mean “failing the WTO and multilateralizm alone.”

“We would also be failing our constituencies at large, the business community and particularly the most vulnerable,” he said.