South Africa said on Wednesday that the United States had granted some local steel and aluminum producers exemptions from tariffs imposed by U.S. President Donald Trump this year.

Trump’s decision to impose a 25 percent tariff on steel imports and a 10 percent tariff on aluminum riled metals producers worldwide, though some major exporting nations secured exemptions for all their steel and aluminum products.

Nickel fell to an 11-month low on Monday on worries about stainless steel, while other base metals were pressured by uncertainty about the global economy.

Aluminium touched the weakest since August last year as speculators piled on more bearish positions.

“The macro pressures continue to weigh on the downside, such as China’s growth situation, Europe’s political uncertainty and also the dollar’s pretty strong,” said Geordie Wilkes, head of research at Sucden Financial in London.

“People are now looking to the G20 for some sort of clarification, but I’m cautious about the negotiations on the (China-U.S.) trade war.”