Fed may not be able to wait on exit: Bullard

President of the Federal Reserve Bank of St. Louis in the U.S. James Bullard attends the European Banking and Financial Forum in Prague, March 29, 2011.

CHICAGO (Reuters) - The Federal Reserve Bank may not be able to wait until uncertainty over several potential global crises recedes before beginning to tighten its ultra-loose monetary policy, a top Fed official said on Wednesday.

Even after the Fed begins withdrawing monetary stimulus, there will still be plenty of accommodation in place, St. Louis Fed President James Bullard said in slides accompanying a speech for delivery in London. Since December 2008, the Fed has kept interest rates near zero and has bought more than $2 trillion in assets to help push borrowing costs down still further.

Since the Fed's most recent round of bond-buying began, the U.S. economy has taken a turn for the better, and prospects for growth this year are reasonably good, he said.

The outlook is clouded by uncertainties posed by a spike in oil prices, Japan's earthquake, tsunami and ensuing nuclear crisis, the U.S. fiscal situation and the ongoing debt crisis in Europe, he said.

Still, the central bank's policy-setting Federal Open Market Committee may need to act before waiting to see how these situations are resolved.

"The FOMC may not be willing or able to wait until all global uncertainties are resolved to begin to normalize policy," Bullard said in the slides.

(Reporting by Ann Saphir; Editing by Leslie Adler)