Brazil has also complained about the flood of money that has driven up the value of the real and raised concerns about asset bubbles. In March, Brazil's finance minister blasted the "monetary tsunami" unleashed by interest rate cuts in the United States, Japan and Europe.

This trend could lead to more outright intervention in the currency market, and maybe even capital controls in some emerging economies, said Julian Jessop, an economist at Capital Economics. But given the dim outlook for global growth, he added, officials in the developed world may not have any other choice but to continue weakening their currencies.

"This might simply be part of the price that has to be paid for a sustained global recovery," said Jessop.