Moody's rating agency Wednesday lowered Japan's debt rating a notch to Aa3 from Aa2, citing its deficits and government debt, but said the outlook is stable. In its announcement, Moody's Investors Service Inc. said the downgrade "is prompted by large budget deficits and the build-up in Japanese government debt since the 2009 global recession." The announcement said several factors make it difficult for the world's third-largest economy (after the United States and China) "to slow the growth of debt-to-GDP (gross domestic product) and thus drive this rating action." Japan's total debt is about 200 percent of its GDP. Japan is recovering from the devastation caused by the March 11 earthquake and tsunami that killed thousands and caused economic damage running into the billions of dollars -- and triggered one of the worst nuclear crises ever at the Fukushima Daiichi nuclear power plant that is yet to be fully contained. "The March 11 earthquake and tsunami, and the subsequent disaster at the Fukushima Daiichi Nuclear Power Station, have delayed recovery from the 2009 global recession and aggravated deflationary conditions," Moody's said. "Prospects for economic growth are weak, making it more difficult for the government to achieve deficit reduction targets and implement its Comprehensive Tax and Social Security Reform plan." The agency said the forecast of stable outlook "comes from the undiminished home bias of Japanese investors and their preference for government bonds, which allows the government's fiscal deficits to be funded at the lowest nominal rates globally." The announcement said the rating action does not affect the Aaa country and bank deposit ceilings, the outlooks for which remain stable. The downgrade, the first such in nine years, came despite the recently announced plan to double the consumption tax rate to 10 percent in stages and help secure funds to cover rising welfare costs, Kyodo News reported. Japanese Prime Minister Naoto Kan, who has been in office only since June 2010, is under intense pressure to resign. Moody's also cited such frequent changes in the administration for its action. The New York Times reported Standard & Poor's had similarly downgraded Japan's ratings to AA in January. On the Tokyo Stock Exchange, investors didn't appear to be affected much by the downgrade. The benchmark Nikkei-225 index was down 16 points, or 0.19 percent, to 8,716 points in early trading Wednesday. Copyright 2011 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.