U.S. Bonds

Roubini said two days ago that in the U.S., a failure to address the budget deficit risks a bond market "revolt." President Barack Obama's administration has been negotiating with Republicans, who control the House of Representatives, over cutting the federal government's long-term shortfall and raising the debt ceiling.

"We're still running over a trillion-dollar budget deficit this year, next year and most likely in 2013," Roubini said in a speech in Singapore on June 11. "The risk is at some point, the bond market vigilantes are going to wake up in the U.S., like they did in Europe, pushing interest rates higher and crowding out the recovery."

In Europe, officials need to restructure the debt of Greece, Ireland and Portugal, and waiting too long may result in a "more disorderly" process, Roubini also said.

European officials are racing to find a plan to stem Greece's debt crisis by June 24 while sharing the cost of a new rescue with bondholders. Saddled with the euro area's heaviest debt load, Greece is seeking additional loans after last year's 110 billion-euro ($159 billion) bailout.

Japan's Contraction

Japan's economy, the world's third-largest, slid into a recession last quarter, using the textbook definition of consecutive quarterly declines in GDP, after the March 11 earthquake and tsunami and ensuing nuclear crisis. The government is spending an initial 4 trillion yen ($50 billion) to clean up from the disaster, which is estimated to have caused as much as 25 trillion yen in economic damage.

Bank of Japan Governor Masaaki Shirakawa said on June 1 that supply constraints are easing faster than expected as companies rush to repair their facilities. The risk in Japan is "if growth fizzles out after a short-term reconstruction stimulus," leading to a renewed struggle to maintain expansion around 2013, Roubini said.

China's economy may face a "hard landing" after 2013 as government efforts to boost growth through investment cause excess capacity, Roubini told reporters after his June 11 speech.

'Overcapacity' In China