President Donald Trump again criticized the Federal Reserve for raising interest rates following the worst market sell-off since February.

"The Fed has gone crazy," he told reporters on Wednesday as he arrived in Pennsylvania for a campaign rally. The central bank "is too tight," he added.

White House Press Secretary Sarah Sanders said in a statement following the close of markets that the U.S. economy is "incredibly strong" despite the sell-off, which analysts attributed in part to trade tensions with China.