The currency's slide to its weakest level in four decades comes as Japanese authorities indicate they may step in to steady the market.
The Japanese yen fell to a 40-year low of 161.6 against the U.S. dollar, underscoring renewed pressure on the currency as Japan signaled possible intervention. The move points to heightened official concern over the pace of yen weakness, which can raise import costs and add volatility across foreign-exchange markets.