"After more than three years of strong growth, the global economy is certainly today at an important juncture," Rato said during a speech at a seminar organised by the Organization of Petroleum Exporting Countries (OPEC).

The IMF's managing director underlined that growth in Europe, Japan, and emerging Asian economies was healthy and sustained.

However, the United States "while still strong is moving towards potential", he said, referring to theso-called potential of an economy, or the maximum capacity of an economy to grow without generating inflation.

"With the housing market in the US pulling faster than anticipated, there is a risk of a bigger than anticipated slowdown in the US economy, which could derail the global expansion."

"Our base forecast is for a continued smooth ride for the global economy. However... there are more clouds on the horizon than a year ago," Rato said..

The IMF and World Bank are due to hold their annual meetings in Singapore from Thursday.

Advanced economies face a challenge in steering the correct course with monetary policy Rato said, underlining signs of inflationary pressures and urging them to be "vigilant".

Emerging nations also needed to to respond swiftly to any signs of a slowdown and encourage domestic demand, he added.