Japan can retain its decade-old blueprint focusing on efforts to beat deflation even if the central bank were to phase out its massive stimulus with an end to negative interest rates, said the government's chief economist Tomoko Hayashi.

Under pressure from then-Prime Minister Shinzo Abe to take bolder steps to beat deflation, the Bank of Japan signed a joint statement with the government in 2013 and committed itself to achieve its 2% inflation target "at the earliest date possible."

The pledge served as the backbone of former BOJ Gov. Haruhiko Kuroda's radical monetary stimulus and justification for keeping Japan's interest rates ultralow.