“We’re going to take the highest year, the biggest purchase that China has ever made with our farmers, which is about $15 billion, and do something reciprocal to our farmers,” the president said. “Our farmers will be very happy. Our manufacturers will be very happy and our government is very happy because we’re taking in tens of billions of dollars. I think it’s working out very well.”

Economists and industry groups were not so sanguine.

“Americans’ entire shopping cart will get more expensive,” said Hun Quach, the vice president of international trade at the Retail Industry Leaders Association, which represents Best Buy, Walmart, Target, Dollar General and other stores.

Rick Helfenbein, the president of the American Apparel & Footwear Association, called the measure a “self-inflicted wound” that he said would be “catastrophic.” While footwear and apparel were largely spared from Mr. Trump’s first two rounds of tariffs, they are on the list of items that would be taxed if the president follows through with his threat to raise taxes on an additional $300 billion worth of goods.

“By tightening the noose and pulling more consumer items into the trade war, the president has shown that he is not concerned with raising taxes on American families, or threatening millions of American jobs that are dependent on global value chains,” Mr. Helfenbein said.

Both China and the United States have left a window for negotiators to try to reach a deal before the latest round of higher tariffs goes into effect. China said it would delay the higher rates until June 1, while Mr. Trump’s new 25 percent rate affects only products sent to the United States as of May 10, leaving a two- to four-week gap from the time most goods leave China by boat to when they arrive at an American port.

But the two sides would have far to go to quickly resolve what has once again become a heated economic dispute. Progress toward a trade agreement between the United States and China nearly collapsed over the past two weeks, after American negotiators accused China of reneging on substantial portions of a potential trade agreement it had previously committed to. Significant differences remain over how tariffs should be rolled back between the countries, and whether the negotiated provisions must be enshrined in Chinese law.

Beijing’s retaliation comes as many in China feel that the United States has behaved highhandedly in threatening tariffs. “Mutual trust and respect are of the essence in handling the negotiations,” said Zhu Ning, a Tsinghua University economics professor.