Japan's foreign-exchange reserves stood at $841.79 billion at the end of October, down $1.77 billion from the month before for the second straight monthly fall, the Finance Ministry said Tuesday.

The ministry blamed the fall on valuation losses in holdings of U.S. Treasuries, driven by U.S. interest rate increases, and the shrinking value of Japan's euro-denominated assets on the euro's slide against the dollar.

The amount of combined foreign-exchange reserves held by China and Hong Kong remained the world's largest at the end of July for the second straight month, topping those held by Japan, previously the largest holder of such reserves, according to the latest comparable International Monetary Fund data.

According to the Finance Ministry report, Japan had $700.39 billion in foreign securities as of Oct. 31, down from $703.35 billion the month before.

Foreign currency deposits stood at $122.78 billion, up from $121.51 billion.