The International Monetary Fund said on Thursday the U.S. economic recovery has proved stronger than expected but is still vulnerable to high unemployment and a moribund housing market.

The IMF raised its U.S. growth forecast slightly to 3.3 percent for 2010 and 2.9 percent for 2011 but said unemployment would remain above 9 percent for both years and inflation would remain low.

In a statement released after its annual consultations with U.S. government authorities the IMF said recovery from recession had become well established due to a powerful fiscal and monetary policy response.

"The outlook has improved in tandem with recovery but remaining household and financial balance sheet weaknesses — along with elevated unemployment — are likely to continue to restrain private spending," the fund said.