A top Federal Reserve official said faster global growth may be keeping inflation higher than expected in the United States.

"Typical estimates suggest inflation should have remained low or even moved lower during 2011," St. Louis Fed President James Bullard said in a speech in Beijing.

One explanation may be that the global gap between actual growth and employment and full economic potential — which is narrower than that of the United States, and may even be positive — is affecting U.S. prices, he said.

The St. Louis Fed president spoke last week to a closed-door gathering. The St. Louis Fed made a copy of his presentation public on Monday.