BBC News | BUSINESS | Bush gaffe hits yen The yen fell as some traders interpreted the comment as meaning the US favoured a devaluation of the Japanese currency.
Bush aides hastened to clear up the confusion, saying the president - in Japan as part of an Asian tour - had "misspoken".
They said his comment had meant to be about Japan's problem of "deflation" - steadily falling prices, which depress spending and investment - not devaluation.