President Donald Trump speaks during a Cabinet meeting on day 12 of the partial U.S. government shutdown at the White House in Washington, January 2, 2019.

President Donald Trump on Friday blamed the stock market sell-off on Democrats' regaining control of the House in the midterm elections in November.

"As I have stated many times, if the Democrats take over the House or Senate, there will be disruption to the Financial Markets," Trump said in a tweet. He added, however, that "things will settle down."

Tweet Friday

U.S. stocks have been under heavy pressure as fears of an economic slowdown, concern over a potential policy mistake from the Federal Reserve and the ongoing trade war with China have sent chills throughout financial markets.

The Dow Jones Industrial Average and S&P 500 last month logged their worst December performances since 1931, both falling more than 9 percent. In the fourth quarter of 2018, the major averages also posted their biggest quarterly losses since the financial crisis.

This is not the first time Trump has gone after Democrats for turmoil in financial markets. On Oct. 30, Trump said the market was taking "a little pause," as people awaited the results of the midterms. "If you want your Stocks to go down, I strongly suggest voting Democrat," Trump said in a tweet back then.

Tweet Oct 30

Trump has also blamed the Fed for the pressure in the stock market. Last year, the central bank raised its overnight rate four times. Last month, Trump tweeted: "The only problem our economy has is the Fed. They don't have a feel for the Market."

Tweet Dec 24

He also characterized last month's sharp pullback as a "glitch," saying on Wednesday: "It's going to go up once we settle trade issues and a couple of other things happen."