Finance Minister Taro Aso said Friday there is no need to fret about every currency move but volatility is undesirable.

"We do not need to be swayed by every rise and fall," Aso told a news conference after a Cabinet meeting while financial markets braced for the inauguration of Donald Trump as U.S. president.

Aso made the comments after Trump's pick for Treasury secretary, Steven Mnuchin, stressed on Thursday the importance of having a strong dollar over the long term. Trump is viewed as favoring a weaker dollar.

Aso said he does not believe Trump and Mnuchin have "differing views" on the dollar.

The yen has been weakening against the dollar since November, when Trump won the presidential election, boosting hopes for U.S. economic growth. A weak yen often boosts the profits of Japanese exporters when repatriated.