Looking for His glorious appearing! Titus 2:13

"If excessive rises or falls in the yen due to speculation cause trouble for a lot of people, intervention would be a powerful tool, so there's no reason why we should not use it," Mr Aso told reporters. His words helped to push the yen down to a two-year low against the dollar.

Mr Aso also said he expects the government to reach an accord with the Bank of Japan next month to double the official inflation target to 2 per cent in order to combat deflation.

Other central bankers have also signalled changes to traditional inflation targeting frameworks. The Canadian central bank chief, Mark Carney, said in a speech in Toronto this month that depressed economies, where interest rates are already at rock bottom, might adopt a nominal GDP target to stimulate growth. Mr Carney will take over as Governor of the Bank of England in July. And the chairman of the Federal Reserve, Ben Bernanke, also committed the US central bank this month to carry on printing money to buy up private sector bonds until the world's largest economy experiences a robust recovery and unemployment falls.

"It's a tug of war at the moment, they're talking currency wars," Dan Harden of Global Reach Partners told CNBC. "The Fed and the Bank of Japan [are] both easing and trying to devalue their currency – at the moment the Japanese are winning."