Bank of Japan Gov. Haruhiko Kuroda said Saturday that he won't hesitate to boost monetary stimulus if needed, reiterating a pledge during an annual policy retreat in Jackson Hole, Wyoming, at which central bankers stressed their need for backup from fiscal policy.

"There is no doubt that there is ample space for additional easing in each of the three dimensions," Kuroda said, referring to the BOJ's package of asset buying, monetary-base guidance and negative interest rates. "The bank will carefully consider how to make the best use of the policy scheme in order to achieve the price stability target," he told the Federal Reserve Bank of Kansas City's symposium.

Central bankers, struggling to spur persistently disappointing growth, gathered in Grand Teton National Park to debate how best to tackle low inflation despite having already cut interest rates to near zero or, in some cases, below zero. They heard Fed Chair Janet Yellen on Friday describe future potential options to jump-start the economy while saying that the case for a U.S. rate hike had strengthened.