Moody’s Investors Service said it has put Japan’s sovereign ratings on review for a possible downgrade.
The rating agency said the review was due to concern over faltering growth in the world’s number three economy and the country’s massive public debt.
It put both Japan’s Aa2 foreign and local currency ratings on review.
Moody’s said Japan’s government lacked an effective strategy to tackle ballooning government debt.
Faced with tumbling output and exports following the March 11 earthquake and tsunami, Japan’s economy recently slipped into a recession after contracting at an annualised rate of 3.7% in the January-March quarter.