He said the Federal Reserve was being "too aggressive" by raising interest rates this year and getting "a little bit too cute". That is a good thing.
A Fed official said the central bank would not comment on the president's remarks.
But those actions have drawn scorn from Trump, who has accused the Fed of moving too fast in raising rates when inflation is minimal and government data points to a strong economy.
Analysts attribute some of the recent share price declines to sales by investors anxious that trade tensions will hurt growth, while trade tariffs and rising interest rates raise costs for businesses.
"I wonder today whether Trump really has some buyer's remorse with respect to selecting Powell as his Fed chairman, because that was a odd pick", Moore said.
The Fed traditionally remains outside the purview of the President, though Trump has at moments blurred the lines by commenting on Fed policy.
"I like low interest rates", Trump said.
When asked about the steep fall of the stock market, Trump said he was not anxious about it.
The Federal Reserve can likely stop raising U.S. interest rates once they reach about 3 per cent, as long as inflation remains around 2 per cent and the economy is doing well, Chicago Federal Reserve President Charles Evans suggested on Wednesday.
The turmoil on stock markets came a day after the International Monetary Fund slashed its global growth forecast on worries about trade wars and weakness in emerging markets.
"Clearly as a result of (rate hikes). we see and we will continue to see capital flow movements", she added. The problem I have is with the Fed.
White House officials, including Mr Trump, have dismissed the declines as standard corrections after a long run of rising share prices.
The US stock market sell-off last night saw the S&P 500 and the Dow marking their biggest daily declines since February 8 with technology stocks at the centre of the falls.
Trump began imposing tariffs on hundreds of billions of dollars worth of Chinese imports in January 2018, with Beijing retaliating by slapping tariffs on United States goods in response.
The Fed's main interest rate, the federal funds rate, now stands between 2 and 2.25 per cent.
The biggest driver for the market over the last week has been interest rates, which began spurting higher following several encouraging reports on the economy. Following a sharp Wall Street sell-off on Wednesday, Trump said the Federal Reserve "is making a mistake".
Interest rates are rising. The central bank expects to raise the federal funds rate one more time in 2018 and three times in 2019.