Many chief executives and trade groups say they support the president’s goal of changing China’s economic practices, particularly those that require businesses to hand over valuable technology as a condition of operating in China. But businesses have begun to express concern about the seemingly unending trade war. Many big companies, particularly those in the retail and manufacturing sectors, have downgraded sales and profit forecasts as a result of the tariffs.

The trade war’s potential to slow America’s economic expansion, including its impact on the manufacturing sector, has already prompted concern from Federal Reserve officials. The Fed cut interest rates for the first time in more than a decade in July, and officials have said they are prepared to cut them further to protect the economy against fallout from slowing global growth and trade risks.

Even some officials who did not vote in favor of July’s rate cut say economic risks have increased.

Eric Rosengren, the president of the Federal Reserve Bank of Boston and a monetary policy voter this year, indicated that he still favored waiting and watching incoming economic data before making interest rate cuts beyond the July move, which he voted against.

But he also said it was “clearly reasonable” to judge that risks to the economy were elevated. “Should those risks become a reality, the appropriate monetary policy would be to ease aggressively,” he said, suggesting that he might favor rapid interest rate cuts if economic data soured meaningfully.

The Trump administration has been pressuring China for more than two years to make a trade deal that would strengthen its protections for American intellectual property and result in large purchases of American products. But the two sides continue to have significant disagreements, including which of Mr. Trump’s tariffs should be rolled back and what kind of legal changes China must make to treat American companies more fairly.