Mr. Xi faces his own pressures. Though he solidified his political base at a major Communist Party meeting last month, he must contend with a maturing economy now saddled with a mountain of debt. He is also leading an ambitious plan to upgrade China’s technological know-how — an effort that could be complicated by a trade fight with the United States.

The two sides took pains on Thursday to show common ground. The Chinese government announced near the end of Mr. Trump’s visit that it planned to reduce tariffs on imported cars and to open up its financial sector to greater competition. But Chinese officials offered no promises on when or how much they might be willing to move on either issue.

The Chinese offers represented a bid to strengthen support for a less assertive American trade policy by reaching out to two industries that have a lot to lose. One is Wall Street, which has profited handsomely from helping Chinese companies and the Chinese government to buy American companies and real estate. The other is Detroit’s automakers, which have seen strong sales in China of cars built almost entirely in Chinese factories by Chinese workers and robots using Chinese parts. Thanks to Chinese tariffs, cars made in the United States are too expensive to compete broadly in China.

But the Trump administration’s negotiators made little attempt during the visit to seek such industry-specific promises, believing that previous efforts had resulted in little progress.

Instead, Mr. Trump oversaw on Thursday the signing of more than $250 billion in largely symbolic business deals.

Most of them appeared to be the kinds of deals that American companies have long struck in China.

Qualcomm, the chip maker, said on Thursday that it had struck deals with Chinese smartphone makers to sell them a total of $12 billion in components over the next three years. Qualcomm already counts on China for more than half of its revenue, and the deals it signed on Thursday were with existing customers.