The global economy is recovering from recession more quickly than expected but rescue efforts have worsened public finances, and if not reined in, will lead to a debt explosion, the IMF said on Wednesday.
Laying out its priorities ahead of annual meetings of global financial leaders in Washington, the Fund warned more must be done to fix an unbalanced world economy and said major currencies would need to weaken to put the balance straight.
Its World Economic Outlook nudged up forecasts for global growth to 4.2 percent this year. But it kept next year's unchanged and officials' stress was on the danger that steps to combat the financial crisis have left no room for maneuver.
Emerging market economies like China and India are leading the upturn, it said, with 2010 growth expected to be nearly three times as fast as that in advanced economies.
But as the world economy slowly makes its way out of recession, IMF chief economist Olivier Blanchard warned that new, and no less formidable, challenges have already appeared.
He said fiscal consolidation must become a priority for heavily-indebted advanced economies but that is likely to further weigh on demand, and thus on economic growth -- a dilemma given many economies are still struggling.
To offset the drag on demand, advanced countries as a whole may need to weaken their currencies to boost exports, Blanchard said. On the other hand, emerging economies need to allow their currencies to rise, curbing exports.
The IMF has for years urged such a rebalancing between surplus countries such as China and those with large deficits, such as the United States. Most of the attention has focused on the need for China to allow its yuan currency to appreciate to help drive domestic demand.
The IMF forecast growth in emerging and developing economies would rise to 6.3 percent this year and 6.5 percent next year. In advanced economies it would reach only 2.3 percent in 2010 and 2.4 percent in 2011.
China will grow the fastest -- by 10 percent this year and 9.9 percent in 2011. Elsewhere, Brazil, India and Indonesia are also staging strong rebounds.
Rich countries are shouldering a much heavier debt burden, with debt-to-GDP ratios approaching World War Two highs. While the IMF urged countries to urgently adopt credible debt-reduction strategies, it said most stimulus measures planned for 2010 should be fully implemented because the recovery remained fragile and unemployment high.
Most advanced economies should embark on a significant fiscal consolidation in 2011, and a few should start sooner.
The IMF's oft-repeated debt warnings have taken on greater significance in recent months as Greece's fiscal woes intensified, driving up its borrowing costs and forcing officials to lay out a possible rescue package.
The global debt reduction task is daunting. Withdrawal of stimulus measures would reduce public spending by only about 1.5 percent of GDP. Countries would need adjustments three times larger than that just to stabilize debt-to-GDP ratios.
Reducing debt to pre-crisis levels, on the other hand, would likely require more painful steps including tax increases and cutbacks on core government programs like social security.
As they stand, typical current entitlement programs imply off-balance-sheet liabilities well in excess of actual public debt, the IMF said.
While it revised up its forecast for the United States, the Fund cautioned that uncertainty about the U.S. outlook remains elevated although less than previously thought.
The euro-area will eke out weak growth both this year and next of around 1 percent, with only Greece's economy left shrinking in 2011 as the bloc emerges from the recession.
By contrast, Australia and economies in Asia are already showing strong growth, the IMF said, although it also said the Bank of Japan may yet have to loosen monetary policy further if deflation persists.
In Sub-Saharan Africa, most economies are expected to stay close to their potential output, while economies of emerging Europe will continue to lag behind, with some exceptions.
The IMF raised its outlook for Latin America and maintained its forecast for the Middle East and North Africa.
(Reporting by Lesley Wroughton and Emily Kaiser; editing by Patrick Graham)