Naoto Kan, Japan’s prime minister, warned that his government was ready to take further “resolute action” in currency markets, despite complaints from US and European politicians about Tokyo’s dramatic unilateral yen-selling intervention.

Speaking to the Japan Chamber of Commerce and Industry on Thursday, Mr Kan said the strong yen and weak stock market had “added to uncertainty” about the Japanese economy, which is still struggling to shake off the effects of its sharpest postwar recession.

Tokyo on Wednesday intervened in currency markets for the first time in more than six years, sending the yen nearly Y3 lower against the dollar to just Y85.52 in a matter of hours. By Thursday morning in Tokyo, the US currency was trading at about Y85.35. Japan’s decision to intervene after the yen hit a series of 15-year highs has been praised by leading exporters, as well as by the Keidanren, Japan’s most influential business lobby.