Japan will lend the International Monetary Fund up to $100bn in temporary funds to help emerging economies weather the global financial crisis, Taro Aso, prime minister, will tell the G20 summit in Washington this weekend.

Mr Aso will call on other IMF member countries to inject additional permanent capital into the fund while offering $100bn (€80bn, £69bn) out of Japan's $980bn in foreign exchange reserves as an interim measure.