(REUTERS) — U.S. President Donald Trump’s Treasury secretary called top U.S. bankers on Sunday amid an ongoing rout on Wall Street and made plans to convene a group of officials known as the “Plunge Protection Team.”

U.S. stocks have fallen sharply in recent weeks on concerns over slowing economic growth, with the S&P 500 index .SPX on pace for its biggest percentage decline in December since the Great Depression.

“Today I convened individual calls with the CEOs of the nation’s six largest banks,” Treasury Secretary Steven Mnuchin said on Twitter shortly before financial markets were due to open in Asia.

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