The Bank of Japan may want to consider buying foreign currency assets to help ease the yen's appreciation, economic and fiscal policy minister Banri Kaieda said.

"Such purchases can be an option for the central bank over the medium to long term," Kaieda said in an interview in Tokyo on Friday. "They would be effective" in curbing the Japanese currency's gains, he said.

Kaieda's remarks come as policymakers struggle to stop the yen's advance and lift the country out of deflation using fiscal and monetary policy steps. The yen appreciated this month to its strongest level against the dollar since 1995, threatening the export-dependent recovery, even after the BOJ loosened credit.