WASHINGTON — Two years ago, some of America’s largest corporations were tearing up their business plans to accommodate President Trump, fearful that he could send their shareholders and customers fleeing with a tweet. Now they have a new strategy: Ignore him.

This week, General Motors became the latest recipient of a barrage of tweets from Mr. Trump, who is angry about the company’s closing of a plant in Lordstown, Ohio. The president told the company to reopen the plant or sell it “fast” to someone who would. He suggested that G.M. shutter a factory in China or Mexico instead.

“What’s going on with General Motors?” Mr. Trump said on Wednesday during a speech at a tank factory in Lima, Ohio. “Get that plant opened or sell it to somebody and they’ll open it.”

G.M. has not budged. After Mr. Trump’s tweets over the weekend, the company issued a terse statement noting that it was relocating workers and that it would be discussing plant closings with the United Auto Workers union. It made no mention of the demands of Mr. Trump. In the past, G.M. has blamed the president’s trade war, including tariffs on steel and aluminum, for raising the company’s costs.