The Bank of Japan raised its economic assessment Monday for all of the nation's nine regions, the first across-the-board upgrade since January 2006, thanks to export and production surges.

In its quarterly Sakura Report on regional economies, the central bank said the economy has "begun to stop worsening, but it still remains in a severe situation," suggesting Japan is picking up from its worst postwar recession, albeit at a slow pace.

The report was released after a meeting of managers from the BOJ's 32 branch offices.