The WTO chief called on countries on Thursday to overhaul global ‌trade rules, telling them the old world order had gone for good, following a year of turmoil sparked by U.S. tariffs ​and wider geopolitical tensions.

Ngozi Okonjo-Iweala set out a list of problems facing the World Trade Organization - including the paralysis of ​its dispute-settlement mechanism - ​at the start of a four-day meeting of the body in Cameroon.

"The world order and multilateral system we used to know has irrevocably changed. We will not get it back ... We ⁠must look to the future," the WTO Director-General said.

Ahead of the session, some diplomats and trade officials warned that without an agreement on reforms, countries could start abandoning the ideal of a rules-based global trade system, and set their own regulations.

The gathering in Yaounde comes amid soaring concerns over the impact of the U.S.–Israeli war ​on Iran,and follows ‌years of stalled multilateral ⁠trade deals.

Okonjo-Iweala said ⁠the body's problems over decision-making needed to be tackled. Its current consensus-based model has been regularly stalled by objections from ​some countries. Some delegates are pushing for the organisation to let groups of members ‌form agreements.

She also said there was a lack of transparency ⁠over which countries were using subsidies.

"Lack of transparency leads to lack of trust, and that breeds suspicions of unfairness and anti-competitive behaviours," Okonjo-Iweala told delegates.

This contributed to a "vicious cycle" of mistrust which was holding back members from agreeing new rules and reforms, she added.

The U.S. supports reforms but is resisting a detailed work plan, while the EU, Britain, and China back one, internal reform documents seen by Reuters show.

"If we don't achieve anything concrete, the WTO will lose its attractiveness and relevancy," Swiss Ambassador Erwin Bollinger said before the session.

UK trade minister Chris Bryant warned of potential fragmentation if no deal is reached.

"My anxiety is if ‌we ministers don't get this week right, you might see a disorderly ⁠collapse of the WTO and some people writing a new rulebook," Bryant ​said.

At the meeting, India is set to oppose U.S. efforts to extend a global ban on cross-border e-commerce duties, which New Delhi says developing nations should be able to impose.

U.S. Trade Representative Jamieson Greer, in a draft statement ​seen in advance ‌by Reuters, is expected to tell members the U.S. is "not interested" in a ⁠temporary extension to the ban, only a permanent ​extension.

(Reporting by Olivia Le Poidevin; Editing by Chris Reese, Lincoln Feast and Andrew Heavens)