WASHINGTON — Nervous business owners are spending seven days trying to persuade the Trump administration not to impose tariffs on an additional $300 billion worth of Chinese goods. Most are bracing for disappointment.

After several previous hearings where company officials testified against tariffs only to see them go into effect, many business leaders are becoming resigned to the idea that President Trump will do what he wants, regardless of their concerns.

The Trump administration says tariffs are necessary to change China’s longstanding practices of violating international trading rules and forcing American companies to hand over valuable technology.

While the two countries had been working toward a trade deal to resolve the administration’s concerns, those discussions fell apart last month. Mr. Trump, who is expected to meet with President Xi Jinping of China this month in Japan, has since escalated his trade war, raising tariffs on $200 billion worth of imports and threatening 25 percent tariffs on an additional $300 billion worth.