The World Trade Organization holds its biggest gathering in four years from Sunday, looking to prove that it still has a role in turbocharging international commerce.

Ministers from WTO member states are gathering in the global trade body's home city of Geneva hoping to breathe new life into the crippled organisation, which has been stuck for years trying to make progress on resolving issues like fishery subsidies.

Russia's war in Ukraine has not curbed the zeal of WTO director-general Ngozi Okonjo-Iweala to press on with the four-day gathering, even if some countries refuse flat out to negotiate directly with Moscow.

"This ministerial conference will have to deal with this climate of acute confrontation and various tensions," Sebastien Jean, professor of industrial economics at the French National Conservatory of Arts and Crafts university, told AFP.

It must also "limit the damage as far as possible, to show that the WTO still can play a useful role," he said, pointing out that the organisation could, for instance, ensure that a lack of coordination does not "exacerbate the ongoing food crisis".

The meeting marks the first ministerial conference for Okonjo-Iweala, the former foreign and finance minister of Nigeria, who took the helm in March 2021.

"Many gaps remain but we are making progress. Let us keep on the pressure, let us keep up the work at this critical juncture," she told diplomats on Tuesday.

"The next hours will be critical... believe it or not, I really think we will do it."

Her drive to restore the WTO's profile has been widely praised, amid the context of multiple crises including the Covid-19 pandemic and growing rivalry between the world's two leading economic powers, the United States and China.

"She has created a set of promises as she wants to see deals concluded," said Manfred Elsig, an international relations professor at the World Trade Institute of Bern University.

"However, she can support and guide the members but cannot take decisions on their behalf," he told AFP.

This 12th WTO ministerial conference will put the global trade body's influence to the test for the first time in years.

The 11th gathering in Buenos Aires in December 2017 ended without a significant agreement.

Since then, the problems have piled up in the WTO's in-tray.

The organisation is especially under pressure to secure a long-elusive agreement to end subsidies that reward overfishing.

"For the WTO, there is a real issue of credibility," a Geneva-based diplomatic source said.

After more than 20 years of negotiations, ministers will try to conclude an agreement even if differences of opinion persist-notably between India and wealthy nations-on the conditions for developing countries.

Failing to secure a fisheries agreement "would be a fatal blow to WTO", said one Geneva-based ambassador.

"Failure will be a clear signal that we are no longer able to negotiate with the whole membership, meaning multilateral negotiations will receive the final nail in the coffin."

The WTO is also trying to make itself relevant in combatting the pandemic.

Four major players in pharmaceutical manufacturing-India, South Africa, the United States and the European Union-have informally been negotiating a proposal for a temporary patents waiver on Covid vaccines.

The notion has been slammed by the big pharma lobby, with the International Federation of Pharmaceutical Manufacturers and Associations saying that weakening intellectual property rights would be counter-productive.

The waiver "is not only the wrong solution, but it is also an outdated proposal that has been overtaken by events, since vaccine supplies are vastly outstripping demand", the IFPMA added.

Meanwhile, non-governmental organisations have slammed a compromise text produced last month as aiming for the lowest common denominator, insisting that any waiver should be permanent and should apply to Covid tests and treatments, in addition to vaccines.

Besides fisheries subsides and the pandemic, agriculture, services, development, food security and least-developed country issues are also on the table.

WTO reform is also looming in the background.

The organisation's appeals tribunal ground to a halt in late 2019, after the United States blocked the appointment of new judges, demanding a dramatic overhaul of the body.

WTO spokesman Daniel Pruzin said there was a "growing cautious optimism" on achieving results at the conference.

Decisions are reached by consensus at the WTO, making conclusions all the harder to attain.