According to Reuters, a senior central banker stressed that the Federal Reserve will only begin tapering when the economy shows clearer signs of improvement and even then it should act slowly.

Governor Jerome Powell called the timing "necessarily uncertain" because it depends on the strength of the recovery, while Boston Fed President Eric Rosengren pointed to the central bank's balance sheet as a reason to be patient as it heads into a policy meeting next month.

"What it's reasonable to expect us to do is to be transparent and to move gradually when it is time to withdraw accommodation, or even to begin reducing the pace at which we add accommodation and go slowly in doing that," Powell told the Asia Economic Policy Conference in San Francisco.