Analysts at Citigroup said on Wednesday that the risk of global recession increased.

"In our view, global growth is at a highly precarious point, after 2-3 years of relative calm," Citigroup said.

"The most recent deterioration in the global outlook is due to a moderate worsening in the prospects for the advanced economies, a large increase in the uncertainty about the advanced economies outlook (notably for the U.S.) and a tightening in financial conditions everywhere," the bank noted.

Citigroup pointed out that the slowdown in the U.S. economy would have a negative impact on the global economic outlook.