“The trade negotiations have gone on for so long because the two countries’ fundamental interests cannot be reconciled,” Nicole Zhang, 26, an employee at an online travel company, said while shopping in a Beijing mall on Friday. “National interests are unfeeling things like that. That’s just how it is.”

At the beginning of the year, China’s position was more defensive. Its economic growth slowed in the second half of last year, in part because tariffs hurt business confidence. Since then, the Chinese government has poured billions of dollars into the financial system and pressed state-run banks into service extending credit.

Officials said last month that the economy grew 6.4 percent in the first quarter of the year, matching the pace from the previous quarter. Industrial output has been solid. Shoppers have opened their wallets.

Still, for many Chinese businesses, especially those that sell overseas, uncertainty remains front of mind. China’s exports to all major regions, not only to the United States, grew more slowly in the beginning of this year. Should the trade war intensify further, China may find it increasingly expensive to prop up its economy, and it could face another slowdown or widespread job losses.

The state news media have worked to reassure the country’s consumers. In a headline published on Friday before the tariffs rose, the People’s Daily newspaper, which is the Communist Party’s mouthpiece, declared that Chinese trade “has positive momentum and strong driving power.”

Some companies with business on both sides of the Pacific are trying to stay positive, too. Née Lau, the owner of Amourvino Winery in Napa, Calif., said the tariffs China imposed last year had hurt his profits. Still, Mr. Lau said he would rather not raise prices, even if it meant earning less for now. Holding onto his overseas dealers and clients, he said, was more important to the long-term health of his business.

“The United States and China will definitely come to some kind of agreement. It’s just a matter of time,” Mr. Lau said. “It’s impossible for a war between two superpowers to go on forever.”