Japan's newly appointed Finance Minister, Naoto Kan, said he wanted the yen to weaken more and would work with the Bank of Japan to bring the currency to an appropriate level given its impact on the economy.
The dollar jumped half a yen after his comments on views the new finance minister will be more inclined to act against excessive yen rises that could hurt the export-driven economy.
It would be nice if the yen weakened a bit more, Kan, who is also deputy prime minister, told a news conference on Thursday.
Kan was named on Wednesday to replace 77-year-old Hirohisa Fujii, who stepped down for health reasons.
The dollar surged to the day's high of 92.87 yen, up from around 92.20 yen before his comments reached the market.
Some analysts say Kan may be less tolerant of a strong yen, which could hurt a fragile export-led economic recovery from Japan's worst recession since World War Two.
In November, when the yen surged to a 14-year high against the dollar, Kan said he hoped the yen would weaken and that the government would try to slow its appreciation, although he didn't elaborate on how that could be done.
A weak yen would benefit Japanese exporters as it boosts the competitiveness of their goods overseas.