SAN FRANCISCO, Nov 5 (Reuters) - The Federal Reserve should wait for stronger evidence of economic momentum before pulling back on its massive bond-buying program, but it should then announce a definitive end to the stimulus, a top Fed official said on Tuesday.
"Once you are kind of clear that the program has achieved its goals, (that) we've gotten the substantial improvement" in the labor market outlook that was sought, the U.S. central bank should announce its expected amount for the cumulative bond buys and over how many months it expects to end the program, John Williams, president of the San Francisco Federal Reserve Bank, told reporters at the close of the bank's Asian Economic Policy Conference.
"Instead of leaving it out in the open to say, 'Let's see how it goes,"' he said, the idea would be to "switch in a way at the end of it from the open-ended to the more closed-ended" style of bond-purchases that the Fed followed in its first two rounds.
If the program was needed in the future, the Fed could start the program again, he said.
(Reporting by Ann Saphir; Editing by Leslie Adler)