A former head of the World Trade Organisation has warned the global trading system is in grave danger as the US considers imposing punitive tariffs.
Mike Moore, who led the WTO between 1999 and 2002, said plans by US president Donald Trump to slap levies on imports of steel and aluminium might trigger a full-scale trade war that in turn could lead to a global recession.
"It could do, it's just how far this guy (Trump) is prepared to go."
"Everyone's now pacing the room and wondering what the hell is happening," Mr Moore said.
"World leaders should show restraint," he said.
He argued they should try to reason privately with the unpredictable Mr Trump about the futility of his proposals, rather than fan the flames with talk of retaliation.
"But you mustn't corner the beast," he said.
"It must be gently done and friends should do it," Mr Moore said. "He's a very unusual man."
He concedes their intervention might not make much difference.
Mr Trump is already under fire from some in his own Republican party, but has shown no sign of backing down.
The WTO, which has been criticised for widening the gap between rich and poor and ignoring the environment, still had a future, Mr Moore said.
"The global trading system is something to treasure and it's delivered to people the highest living standards."