A clerk sorts $100 banknotes at the headquarters of Hana Bank in Seoul, April 3. Yonhap

Korea's foreign reserves declined in April due to a fall in deposits and the conversion value of non-dollar assets, central bank data showed Tuesday.

The country's foreign reserves had come to $413.26 billion as of end-April, down $3.51 billion from the previous month, according to the data from the Bank of Korea (BOK).

The central bank said deposits increased and the converted value of holdings denominated in other currencies also fell due to a rise in the dollar's value.

The dollar index that gauges the greenback's value against major peers rose 1 percent last month, the central bank said.

Foreign reserves consist of securities and deposits denominated in overseas currencies, International Monetary Fund reserve positions, special drawing rights and gold bullion.

Foreign securities, such as U.S. Treasuries, had been valued at $370.61 billion as of end-April, up $5.73 billion from a month earlier. They accounted for 89.7 percent of foreign reserves, the data showed.

The value of deposits stood at $18.85 billion at the end of April, down $11.69 billion over the cited period.

Korea ranked as the world's ninth-largest holder of foreign reserves at the end of March, the BOK said. (Yonhap)