BOJ Kuroda: Tapering asset buying an option in ending quantitative easing

But he stressed anew that it was too early to debate the timing, method and means to end quantitative easing (QE).

On criticism that the BOJ's massive purchases were drying up liquidity in Japan's government bond market, Kuroda said low volatility helps spur economic activity.

"But whether volatility will stay low is another problem, so we are always closely monitoring market liquidity," he told parliament.

(Reporting by Leika Kihara)