After a week of modest gains, major stock indexes plummeted on Friday as China retaliated against U.S. tariffs by imposing $75 billion worth of tariffs on U.S. goods coming into the country.

China’s foreign ministry said that it would resume tariffs on U.S. imports of automobiles and auto parts and place an additional 5% or 10% tariff on agricultural and food products like soybeans, coffee, whiskey and seafood.

The trouble was exacerbated by statements on President Donald Trump’s Twitter account, which called for the U.S. to “immediately start looking for an alternative to China.” The president also accused China of stealing “our Intellectual Property at a rate of Hundreds of Billions of Dollars a year.”

Our Country has lost, stupidly, Trillions of Dollars with China over many years. They have stolen our Intellectual Property at a rate of Hundreds of Billions of Dollars a year, & they want to continue. I won’t let that happen! We don’t need China and, frankly, would be far…. — Donald J. Trump (@realDonaldTrump) August 23, 2019

The attacks sent markets into a tailspin. The Dow Jones Industrial Average fell by as much as 700 points before closing the day slightly down only 623 points at 25,628.60. Meanwhile the S&P 500 Index fell 75.84 points to end the day at 2,847.11 and the Nasdaq dropped 239.62 points to close at 7,751.77.

The declines come on top of a dismal week of economic reports for the U.S. Earlier, the number of jobs the country had added over the past year was revised downward by 500,000. Meanwhile, the national debt is ballooning at a faster rate than expected, with the U.S. deficit expected to hit $1.2 trillion by 2020.