Over the weekend, some of Mr. Trump’s advisers tried to somewhat soften the blow of the president’s words.

Treasury Secretary Steven Mnuchin, speaking on “Fox News Sunday,” said that Mr. Trump had the authority to make such a demand if he declared a national emergency but that he had not yet done so.

“I think what he was saying is he’s ordering companies to start looking because he wants to make sure — to the extent we are in an extended trade war — that companies don’t have these issues and move out of China,” Mr. Mnuchin said. “And we want them to be in places where they are trading partners that respect us and trade with us fairly.”

There is still significant uncertainty on how many of the steps that China and Mr. Trump have announced will come into effect. The president has stepped back or delayed previous tariffs. And on Sunday the president said he was having “second thoughts” about the threats he made last week. But shortly thereafter, the White House press secretary, Stephanie Grisham, said that the president’s regret was that he had not raised tariffs even further.

American businesses have already begun taking steps to respond. The toymaker Hasbro said last month that it was planning to shift a significant portion of its manufacturing from China to other Asian countries by 2020.

The American toy industry is particularly reliant on Chinese factories, which account for 88 percent of its production, according to the National Retail Federation. But the figures are also large for other major portions of the retail industry.