China announced on Friday that it would retaliate against President Trump’s next two batches of tariff increases on Chinese goods.

The Chinese Government said it would impose extra tariffs of 5% or 10% on $75bn worth of U.S. goods.

The new tariffs will take effect on Sept. 1 and on Dec. 15, according to the government, which did not provide the value of how much would be penalized in the first batch and how much in the second. Those are the same dates when Trump’s next batches of 10% tariffs are scheduled to take effect. 

Trump responded to China’s announcement with a series of angry tweets. “We don’t need China and, frankly, would be far....better off without them,” he wrote.

He included a directive, too. “Our great American companies are hereby ordered to immediately start looking for an alternative to China, including bringing....your companies HOME and making your products in the USA,” he wrote.

The news from Beijing sent markets lower in Europe in afternoon trading there. Futures markets indicated that Wall Street would open lower, too.

Trump had originally threatened to impose the extra tariffs at the start of September. But he delayed more than half the tariffs until December and canceled them entirely for a few categories, so as to allow time for U.S. stores to stock up before the Christmas shopping season.