The International Monetary Fund (IMF) has urged Japan to adopt more aggressive measures to rein in the country's massive public debt. The IMF issued a revised economic forecast for Japan on Wednesday saying its economy will shrink below one percent this year due to March 11 earthquake and tsunami. It had earlier predicted that Japan's economy would grow by 1.4 percent. However, the IMF said Japan's economy will rebound once the reconstruction efforts begin later this year, and expects it to expand 2.9 percent in 2012.