US stocks saw their worst day in monthsafter the White House found itself engulfed in fresh controversy.
Mr Trump's plans to cut taxes and loosen regulation may now be delayed, or simply not come to fruition, some investors fear.
By the closing bell all the major indices were sharply lower, with the Dow Jones down 370 points or 1.76% at 20,609,the S&P 500 down 43 points or 1.81% at 2,357, and the Nasdaq was 158.63 points or 2.57% lower at 6,011.
Bank stocks - which have outperformed the rest of the market in recent months - suffered most.
Bank of America was down 5.9%, Goldman Sachs lost 5%, and Wells Fargo slipped 1.9%.