The Bank of Japan has made a surprise move to boost growth, as the economy continues to struggle.
The bank is to expand its asset purchase programme by 10 trillion yen.
Data issued on Monday showed Japan's economy shrank by 2.3% in the last three months of 2011.
The bank also left rates unchanged at between zero and 0.1%.
The Bank of Japan says it will use the extra funds to purchase Japanese government bonds.