GENEVA(Reuters) - A former World Trade Organization boss has said the future terms of global trade, rocked by U.S. President Donald Trump's sweeping protectionist tariffs, could be decided outside the 30-year-old international watchdog unless it reforms itself fast.

The speech late on Thursday by Roberto Azevedo, who stepped down as director-general in 2020 during Trump's first term, was summarised by trade sources who attended a WTO anniversary event.

He said a loss of appetite for shared global trading rules could encourage the creation of a replacement for the WTO that would exclude some current members, adding, according to his team: "If we don't change, we are dead."

The current WTO director-general, Ngozi Okonjo-Iweala, told members that a reform process must begin in Geneva ahead of a ministerial meeting in Cameroon next year.

"We need to formulate the right questions to be answered ... and put in place a member-owned process to drive it," she said.

Global markets were ending the week as they began, in turmoil, despite a brief respite on Wednesday after Trump paused duties above 10% for most countries except China.

Until now, talks on updating WTO rules have struggled partly because all 166 members must agree by consensus. Efforts to fix its top appeals court, paralysed by Trump in his first term, have failed.

Supachai Panitchpakdi, director-general from 2002-2005, said members must reform the WTO urgently.

"It's either that or we go into a big recession ... even worse than the last 2008 financial crisis, because this time it will be trade-led ... And then there's no way to pull out," he told Reuters.

He proposed to trade delegates on Thursday a month of tariff talks among members, followed by short discussions to reduce barriers and establish new trade rules.

At the same event, a group of 39 states including China, Canada and Britain voiced support for the WTO and called for "bold, collective action" to ensure it remains the bedrock of a free, fair and rules-based system.