The International Monetary Fund raised its global growth forecast for the first time in more than a year, with the U.S. boosting the outlook while recent improvements remain “very fragile.”

The world economy will expand 3.5 percent this year, compared with a January projection of 3.3 percent, the Washington-based IMF said today, April 17 in its World Economic Outlook. It sees growth of 4.1 percent in 2013, up from 4.0 percent. It raised its forecasts for the U.S. to gains of 2.1 percent this year and 2.4 percent in 2013.

The report reflects the IMF’s view that the euro area, while still facing an economic downturn and the “hard to quantify” potential risk of a country’s default, has stabilized since last year. The euro area economy is projected to decline by 0.3 percent in 2012, an improvement from the 0.5 percent in the IMF’s previous forecast. China is projected to grow 8.2 percent and Japan 2 percent this year, Bloomberg reported.