The yen maintained its overnight weakness and briefly touched ¥133 against the U.S. dollar Tuesday in Tokyo, trading at a fresh 20-year low on speculation that the interest rate gap between Japan and the United States will widen.

The Japanese currency mostly traded in the upper ¥132 zone against the dollar in Tuesday trading — its lowest level since April 2002 — as expectations grew that the U.S. Federal Reserve will continue its aggressive monetary tightening.

Senior Japanese government officials said they were closely watching currency markets Tuesday having returned to a heightened state of alert following the renewed slide in the yen.