The yen has fallen to a new 20-year low against the dollar. Investors are selling the Japanese currency and buying the greenback to lock in higher US yields.
The yen weakened to the 135-to-the-dollar level at one point during Tokyo trading on Monday. That is the lowest since February 2002.
The widening gap between interest rates in the United States and Japan is attracting investors to dollar assets.
The Federal Reserve is tightening monetary policy to curb inflation, while the Bank of Japan plans to continue massive monetary easing.