The IMF on Wednesday called for the Group of 20 to boost growth, warning of risks to the global economy, from deflation in Europe to high volatility in emerging economies.
The International Monetary Fund said advanced economies, which include most of the G20, are still leading a pickup in economic growth overall around the world.
But it said more coordinated work is needed to keep output expanding and boost demand, as the world economy still struggles to leave behind the financial crisis that began in 2008.
"The recovery has been disappointing, with G20 output still below longer-term trend," the IMF said in a report ahead of a meeting of G20 finance ministers and central bankers in Sydney beginning Saturday.
"Joint action is needed to boost output and to lower global risks substantially through more balanced growth."
Despite the eruption of more financial turmoil in emerging-market economies last month, the IMF stuck to its forecast of the world's economy expanding 3.7 percent this year, after a 3.0 percent pace in 2013.
It said it was assuming that the volatility that has unnerved emerging economic powers like Indonesia, Brazil and South Africa would be short-lived.
But it suggested that also depended upon further reforms in those economies as well as more work to boost demand in advanced countries.
"The recovery is still weak and significant downside risks remain," the Fund said, citing capital outflows, higher interest rates, and sharp currency depreciation in emerging economies as a "key concern".
It said that tighter financial conditions globally, led by the US Federal Reserve's "tapering" of its stimulus, could further undercut growth in a number of countries.
In addition, extremely low inflation in Europe has the IMF worried about how an unanticipated shock to the economy could push the region into deflation, reversing many of the gains of the past year.
"The euro area is turning the corner from recession to a weak recoverythat remains uneven and fragile," it said.
It said that advanced economies need to maintain easy-money policies to keep boosting demand and enable government to improve their fiscal balances.
Facing tighter monetary conditions, emerging economies meanwhile need to do more work on their own economic policies and management to build their credibility with markets.
The IMF added, too, that advanced economy central banks in the process of pulling back from crisis-era monetary polices, like the Fed with its huge stimulus program, could do well to better coordinate and communicate their actions to reduce the shock effect on the rest of the world.
"There is scope for better cooperation" between central banks on reeling back stimulus programs and tightening ultra-low interest rates, so-called unconventional monetary policies, the IMF said.