Tokyo, Jan. 17 -- Japan faces unforeseen risks in guiding economic policy as its population of about 126 million ages and declines, the governor of its central bank said Thursday.

Bank of Japan Gov. Haruhiko Kuroda told fellow financial leaders Thursday that policies must be devised to prevent the shrinking population from hindering economic growth.

Since taking his post in April 2013, Kuroda has flooded Japan's economy with cash through central bank asset purchases to help fight deflation and keep the economy growing. The BOJ also imposed a negative interest rate policy to keep lending costs ultralow in the longer term.

Kuroda told a seminar that while the conventional strategy of controlling short-term interest rates is well understo...