The Bank of Japan will not risk worsening its balance sheet by increasing its outright purchases of government bonds or by raising its purchases of banks' shareholdings, BOJ Gov. Masaru Hayami said Tuesday.

Hayami's remarks come amid mounting calls from politicians for the BOJ to step up its reflationary policies to prop up the stagnant economy.

"If long-term interest rates increase by 1 percent, the BOJ would lose 1 trillion yen," Hayami said at a regular news conference. "Increasing government bond holdings is rather at odds with the rules of fiscal health, and such action is not necessary at this time.