The Bank of Japan has "many options" for additional easing, Gov. Haruhiko Kuroda said, emphasizing that the bank will adjust its policy as needed to reach its 2 percent inflation target.

"We have substantially increased our JGB holdings but still it's about 20 percent of total JGBs outstanding," Kuroda said in response to questions after delivering a speech Wednesday in New York, noting that the Bank of England holds roughly 40 percent of government debt. "Our purchases of CP, corporate bonds, ETFs and J-REITs have been quite small compared to the market size."

Kuroda's comments come amid increasing signs of doubt at the BOJ that it will achieve its two-year time frame for the target.