Bank of Japan Governor Masaaki Shirakawa said on Monday that the Japanese consumer prices have been "steadily contracting" since the summer of 2009.

Shirakawa also said in his speech in Tokyo that the central bank is making every efforts to overcome the country's deflation, by following its February decision to introduce a 1 percent inflation goal and take additional monetary easing steps.

Japan's deflation has continued for more than 10 years, with its year-on-year rate of change in the consumer price index, excluding fresh food, at around zero percent.

The BOJ will release a semiannual report with forecasts for economic growth and price changes at its next policy meeting on April 27.