The Federal Reserve's $600 billion bond buying program has been at least modestly successful so far, St Louis Fed President James Bullard told the CNBC TV business channel on Monday.

Bullard said nominal interest rates alone should not be used to judge the program's success.

He said economic growth would likely be stronger next year than was anticipated even a few months ago.

I do think GDP growth will be stronger in 2011 than people thought, and a lot of it is because the holiday season is looking pretty good, he said. But it is going to be a slow process.

(Editing by Jeffrey Benkoe)