Europe should boost the total firepower of its rescue fund and frontload its funding to send a positive signal to investors and international partners that it is determined to solve its debt crisis, Japanese officials said on Monday.

Japan has repeatedly expressed its willingness to help Europe contain its debt crisis, but has also stressed it wanted to see a convincing action plan before making any firm commitments. Lifting the combined size of the current bailout fund and the new permanent European Stability Mechanism beyond the current 500 billion euros would be a major step and an encouraging signal.

European leaders agreed in Brussels earlier this month to accelerate the launch of the ESM by a year to mid-2012 with an effective lending capacity of 500 billion euros, but questions have arisen about the size and timing of contributions. Japanese officials said that while bringing forward the launch of the fund was positive, a more ambitious ceiling might be needed given that Europe had little success in bringing in outside investors to boost the firepower of the EFSF fund.