WASHINGTON (MarketWatch) - San Francisco Federal Reserve Bank President John Williams said Friday he now supports another round of asset purchases. "It seems like if we have the tools to move us faster toward our goals, we should use them," Williams said in an interview with the San Francisco Chronicle. Williams is a voting member of the interest-rate setting Federal Open Market Committee this year. Earlier this week, Boston Fed President Eric Rosengren also came out in support of QE3. Both Williams and Rosengren said they favor an "open-ended" program of monthly purchases. The first two rounds of quantitative easing ended on a specific calendar date. Top economists are split fairly evenly on whether the central bank would launch another round of stimulus, according to Blue Chip Economic Indicators.