Japan's foreign-exchange reserves were $837.72 billion at the end of March, down $2.85 billion from the previous month for the third straight month of decline, the Finance Ministry said Thursday.
The ministry attributed the fall to a decline in the value of the euro against the dollar, which deflated euro-denominated assets held by the Japanese government.
Recent spikes in U.S. interest rates also diminished the value of Treasury bonds held by the government, the ministry said.
The March figure marked Japan's sixth-largest foreign-exchange reserves on record. A record $844.54 billion was registered in December.
Despite the contraction, Japan remained the largest holder of foreign reserves of any country or territory for the 64th straight month, the ministry said, citing the latest comparable data.
The ministry said Japan had $696.13 billion in foreign securities at the end of March, down from $696.63 billion a month earlier.
Foreign currency deposits stood at $122.42 billion, down from $123.85 billion.