A Bank of Japan board member on Wednesday advocated a pre-emptive further easing in monetary policy, warning that the need for additional stimulus is growing as the pain from the U.S.-China trade war on the export-reliant economy broadens.

But Goushi Kataoka, a vocal supporter of aggressive easing, offered few clues on whether he will propose loosening policy at this month's rate review, saying he will take into account not just the benefits but the cost of additional easing.

"Personally, I feel the need for additional easing is heightening. On the other hand, many central banks are ramping up stimulus, which could affect the global economy," Kataoka told reporters after meeting business leaders in Hakodate, Hokkaido.