The BOJ's decision comes just ahead of the U.S. Federal Reserve's policy meeting, where the central bank is expected to keep its benchmark interest rate steady.

The Bank of Japan kept interest rates steady on Wednesday and warned of heightening global economic uncertainty, suggesting the timing of further rate hikes will depend largely on the fallout from potentially higher U.

The Bank of Japan (BOJ) on Wednesday kept its key policy rate unchanged at 0.5% in a unanimous vote, in line with market expectations.