ZURICH, Switzerland ꟷ UBS CEO Sergio Ermotti said Wednesday that market volatility could intensify in the second half of the year, but he does not believe the U.S. is heading into a recession.

Global equities saw sharp sell-offs last week as investors digested weak economic data out of the U.S. which raised fears about an economic downturn in the world's largest economy. It also raised questions about whether the Federal Reserve needed to be less hawkish with its monetary policy stance. The central bank kept rates on hold in late July at a 23-year high.

When asked about the outlook for the U.S. economy, Ermotti said: "Not necessarily a recession, but definitely a slowdown is possible."

"The macroeconomic indicators are not clear enough to talk about recessions, and actually, it's probably premature. What we know is that the Fed has enough capacity to step in and support that, although it's going to take time, whatever they do to be then transmitted into the economy," the CEO told CNBC on Wednesday after the bank reported its second-quarter results.

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