Japan's central bank has ended a two-day policy meeting with an upbeat assessment for the world's No. 3 economy and a pledge to persist with its aggressive monetary easing policies aimed at ending years of growth-sapping deflation.

The Bank of Japan said Tuesday that the economy was picking up, supported by government and consumer spending, and it expects the rate of change in the inflation benchmark to "gradually turn positive."

However it noted a "high degree of uncertainty" for Japan, as well as the U.S., Europe and emerging economies, and lackluster activity in Japanese manufacturing.

The stronger assessment followed a revision of data to show growth recovered to 4.1 percent in January-March, raising hopes that Prime Minister Shinzo Abe's heavy-spending recovery strategy may be helping end a two-decade-long slump.