Light is cast on a Japanese 10,000 yen note as it's reflected in a plastic board in Tokyo, in this February 28, 2013 picture illustration. REUTERS/Shohei Miyano/File Photo

FRANKFURT (Reuters) - Japan is concerned about the “speculative” and abrupt firming of the Japanese yen and will respond if necessary to stem the currency’s rise, Finance Minister Taro Aso told a news conference in Frankfurt on Tuesday.

“The economy is a living animal... one-sided, abrupt movements could have adverse impact on the economy, which is not desirable,” Aso said, adding that any steps taken will be in accordance with G20 agreements.

Speaking alongside Aso, Bank of Japan Governor Haruhiko Kuroda added that the bank would not hesitate to take additional steps to achieve its inflation target.

The yen surged to a 18-month high against the dollar after the BOJ held off from expanding monetary stimulus last week, defying market expectations for action even as soft global demand, an unwelcome rise in the yen and weak consumption threatened to derail a fragile economic recovery.