TOKYO - Japan said Thursday it may provide up to US$50 billion (S$63 billion) to the International Monetary Fund to help fight Europe's debt crisis, but the exact figure is yet to be decided.

"Japan is studying the specific figure it will provide to the IMF but it won't be possible for us to reach agreement by the time the finance minister attends the G20 meeting this weekend," said a finance ministry official.

The IMF - which along with the European Central Bank and EU makes up the "troika" of bailout contributors - said in January it was seeking to increase its lending capacity by up to $500 billion to confront the debt crisis.

IMF chief Christine Lagarde and her top staff have been polling G20 leaders to see if they will contribute, but the United States has already said it has no plans to provide more cash.

Japan's finance minister Jun Azumi said this week the G20 is not yet ready to agree on providing more funds to the IMF, while China and Japan - two of the fund's biggest contributors - share the view that "there may still be some room for Europe to make efforts" to deal with its debt crisis.

Azumi said this weekend's meeting with his G20 counterparts in Mexico City would give them a chance to "examine progress in the European situation".

Japan said it expects to pay for the latest contribution by using a refund from the $100 billion it gave to the IMF in 2009 to fight the financial crisis.