Monetary easing in the developed world could cause overheating and asset bubbles in emerging economies, the International Monetary Fund's managing director said in Tokyo on Sunday. "Accommodative monetary policies... could strain the capacity of those economies to absorb the potentially large flows and could lead to overheating asset price bubbles," Christine Lagarde said. Critics in emerging nations have argued that easing measures, particularly in the United States, have driven down the value of the dollar and sparked huge capital flows to spill across their borders, raising the risk of overheating and driving up national currencies. On Friday, Brazilian Finance Minister Guido Mantega warned that his country would take "whatever measures it deems necessary" to fight the problem. "Emerging markets can't passively endure large and volatile capital flows and currency fluctuations caused by rich countries' polices," he said at the IMF and World Bank's annual meetings in Tokyo, which wrap up Sunday. "Advanced countries cannot count on exporting their way out of the crisis at the expense of emerging-market economies." Mantega added that: "Currency wars will only compound the world's economic difficulties." However US Federal Reserve chief Ben Bernanke on Sunday rejected claims that central bank easing in rich countries was to blame for the huge waves of capital flowing into the developing world. "The linkage between advanced-economy monetary policies and international capital flows is looser than is sometimes asserted," he said in a statement. The top US central banker added that the "beneficial effects" of the Fed's policies in propping up the US economy -- the world's biggest and a key developing world export market -- should be given "appropriate weight".