U.S. Federal Reserve Chairman Alan Greenspan says the United States has weathered two years of sharp rises in fuel and natural gas prices reasonably well, thanks to what he calls "market flexibility."

In a speech Wednesday in Washington, Mr. Greenspan also praised market flexibility for what he termed "the impressive performance" of the U.S. economy over the past 20 years.

Analysts have often praised Mr. Greenspan, who has been in office since 1987, for fostering economic stability with his interest rate and monetary policy.

On Wednesday, he made no mention of interest rates, which the Federal Reserve has raised several times in recent months.

Mr. Greenspan's term on the Federal Reserve's Board of Governors is scheduled to end on January 31.