A prolonged U.S. budget standoff would hit global markets very hard, the Bank of Japan warned on Friday as it said it was ready to top up its existing massive stimulus if the recovery underway in the world's third-largest economy was threatened.

But for now, BOJ Governor Haruhiko Kuroda saw no need to ease policy further as Japan was on the path to escape deflation and, if international risks receded as hoped, government fiscal stimulus would further boost growth next year.