The Bank of Japan's decision last week to tweak its bond yield control policy was aimed at making its massive stimulus more sustainable, not a prelude to an exit from ultralow interest rates, its Deputy Gov. Shinichi Uchida said Wednesday.

Uchida said there was still a long way to go before conditions fall in place for the BOJ to raise its short-term interest rate target from the current minus 0.1%.

"We made our policy more flexible to patiently continue with monetary easing," Uchida said. "Needless to say, we do not have an exit from monetary easing in mind."