G20 finance ministers gather in Shanghai from Friday with the global economy assailed on multiple fronts, from China's slowing growth to weak commodity prices, amid simmering disagreements over how best to face the challenges.
The International Monetary Fund (IMF) on Wednesday warned risks of a "derailed recovery" are growing, citing China's faltering economy, falling oil and commodities prices and financial market turbulence.
That came after the 34-member OECD cut its 2016 global growth forecast from 3.3 percent to 3.0 percent.
Ahead of the G20 meeting among the gleaming towers of Shanghai's financial district, the IMF said: "Strong policy responses both at national and multi-lateral levels are needed to contain risks and propel the global economy to a more prosperous path."
The G20 -- which groups 19 countries and the European Union -- was born in the wake of the 1997 Asian financial crisis and upgraded to a summit of leaders in 2008 to tackle the global financial crisis.
Now, global oil prices are at multi-year lows, the threat of Britain leaving the European Union in a possible "Brexit" is looming, and world bourses have tumbled since the start of the year.
US Treasury Secretary Jacob Lew denied the situation had reached crisis levels, but chided other countries for relying too heavily on the United States to be the main engine for global growth.
"We can't be the consumer of first and last resort. There needs to be more," he told Bloomberg Television in an interview.
"It means that in countries that are big economies, regions that have big economies, they need to use policy tools."