The World Trade Organization chief voiced cautious optimism Sunday as global trade ministers gather to tackle food security threatened by Russia's invasion of Ukraine, overfishing and equitable access to Covid vaccines.

Speaking just hours before the opening of the WTO's first ministerial meeting in nearly five years, Ngozi Okonjo-Iweala acknowledged that "the road will be bumpy and rocky, there may be a few landmines on the way."

But she told journalists she was "cautiously optimistic that we'll get one or two deliverables", adding she would consider that "a success".

With its first ministerial meeting in years, the WTO faces pressure to finally eke out long-sought trade deals and show unity amid the still raging pandemic and an impending global hunger crisis.

Top of the agenda as the four-day meeting kicks off is the toll Russia's war in Ukraine, traditionally a breadbasket that feeds hundreds of millions of people, is having on food security.

EU trade commissioner Valdis Dombrovskis said the bloc had been "working hard with all the members to prepare a multilateral food security package," and slammed Russia for "using food and grain as a weapon of war".

The WTO is hoping to keep criticism of Russia's war in Ukraine to the first day of talks, when many of the more than 100 ministers due to attend are expected to issue blistering statements.

But with many flatly refusing to negotiate directly with Moscow, there are fears this could bleed into the following days, when the WTO wants to focus on nailing down elusive trade deals.

"There is a real risk that things could go off the rails next week," a Geneva-based diplomatic source said.

Fisheries deal in sight?

The tensions have not curbed Okonjo-Iweala's zeal to press for agreements on a range of issues during the first ministerial gathering on her watch, especially as the global trade body strives to prove its worth after nearly a decade with no new large trade deals.

There is cautious optimism that countries could finally agree on banning subsidies that contribute to illegal and unregulated fishing, after more than 20 years of negotiations.

The WTO says talks have never been this close to the finish line, but diplomats remain cautious.

The negotiations "have made progress recently, but these remain difficult subjects," a diplomatic source in Geneva told AFP.

One of the main sticking points has been so-called special and differential treatment (SDT) for developing countries, like major fishing nation India, which can request exemptions.

A draft text sent to the ministers for review proposes exemptions should not apply to member states accounting for an as yet undefined share of the global volume of fishing.

The duration of exemptions also remains undefined.

Environmental groups say anything beyond 10 years would be catastrophic. India has demanded a 25-year exemption.

India 'creating problems'

"Twenty-five years is an unreasonable length of time," Isabel Jarrett, head of the Pew Charitable Trusts' project to end harmful fisheries subsidies, told AFP, warning so much leeway would be "devastating for fish stocks".

Colombian Ambassador Santiago Wills, who chairs the WTO fisheries subsidies negotiations, stressed the urgency of securing a deal.

"The longer we wait, the more the fish lose. And the more the fish lose, the more we all lose," he said in a statement Saturday.

India however appears to be stubbornly sticking to its demands on fisheries and in other areas, jeopardising the chances of reaching deals since WTO agreements require full consensus backing.

"There is not a single issue that India is not blocking," a Geneva-based ambassador said, singling out WTO reform and agriculture.

A source with knowledge of the negotiations towards a text on food security also said "the Indians are still creating problems".

Elvire Fabry, a senior research fellow at the Jacques Delors Institute, said India had appeared eager to "throw more weight around" in international organisations, warning New Delhi was capable of scuppering talks.

Patent waiver?

The ministers are also set to seek a joint WTO response to the pandemic, although significant obstacles remain.

Back in October 2020, India and South Africa called for intellectual property rights on Covid-19 vaccines and other pandemic responses to be suspended in a bid to ensure more equitable access in poorer nations.

After multiple rounds of talks, the European Union, the United States, India and South Africa hammered out a compromise that has become the basis for a draft text sent to ministers.

The text, which would allow most developing countries, although not China, to produce Covid vaccines without authorisation from patent holders, is still facing opposition from both sides.

Britain and Switzerland are reluctant to sign up, arguing along with the pharmaceutical industry that the waiver would undermine investment in innovation.

Public interest groups meanwhile say the text falls far short of what is needed by covering only vaccines and not Covid treatments and diagnostics.

"The negotiations are still aeons away from ensuring access to lifesaving Covid medical tools for everyone, everywhere," medical charity Doctors Without Borders warned.