US Federal Reserve vice chairman Stanley Fischer said the commodity boom for Australia and other mineral exporters has ended and is tipping a prolonged downturn in prices as construction investment in Asia subsides. 
In an Asia policy speech on Thursday, Mr Fischer said emerging economy demand for commodities pushed up prices sharply for the past decade, supporting economic growth in developing economies and "commodity sectors in certain advanced economies, including Australia".
More recently, commodity prices for iron ore, coal, oil and gas have slumped, due to expanding global supply and China's economy slowing and shifting from being investment-led to consumption-driven. The downturn in prices has hurt the shares of mining giants BHP Billiton and Rio Tinto, cut federal government revenues and slowed down the local economy.
Mr Fischer, a former World Bank chief economist and who served as governor of the Bank of Israel from 2005 to 2013, signalled that, outside of oil, the low commodity prices would persist for years to come.
"While the path ahead for commodity prices is, as always, uncertain, declining investment rates in emerging Asia, particularly China, present the prospect of a prolonged decline in the growth rate of commodity demand," Mr Fischer said at the Federal Reserve Bank of San Francisco on Thursday.
"And prices could remain low for quite some time, which seems particularly true for metals, such as copper and steel, used heavily in construction and investment."
The price of iron ore, Australia's largest commodity export, plunged to as low as $US45.44 a tonne on Friday, from $US90 a year ago and a peak of around $US187 in   February 2011.
Commodity producers are facing a perfect storm: softening demand from a slowing China, a huge expansion in supply and a US dollar that is surging on expectations that the US Federal Reserve will begin lifting interest rates next month.
China's demand for commodities is slowing as policy markers try to shift the economy from being fuelled by investment in fixed assets like roads, buildings and bridges to consumption-led.
However, Mr Fischer signalled this did not necessarily mean crude oil prices would remain at ultra low levels.
The price of Brent crude, the global benchmark, has sunk about 60 per cent since mid-2014, to $US44.29 on Friday.
"On a per capita basis, China's consumption of oil remains far below that of advanced economies, in line with China's lower rate of car ownership," he said.
"Per capita oil consumption tends to increase with wealth, such that further income growth in China has the potential to provide strong support for the oil market in the coming years."
He added that China would grow faster than the global economy for some time and that its importance to the world would increase.
As the world prepares for the Fed to raise interest rates for the first time in a decade as soon as next month, Mr Fischer gave a strong hint of the bank's intentions. He said some major central banks will begin gradually moving away from near-zero interest rates in the "relatively near future".
He said there was a question if Asian emerging economies were prepared for a move, but the Fed had "done everything we can to avoid surprising the markets".