Days before President-elect Donald J. Trump takes office, China is gearing up for economic battle with the United States.

It threatened a widespread investigation into American chipmakers. It zeroed in on one American retailer, accusing it of “inappropriate conduct” that could lead to sanctions usually reserved for weapons sellers. And it got ready to slap duties on imports of industrial plastics.

The flurry of retaliatory gestures, all delivered this week, could have far-reaching implications for American companies. They join other measures by China in recent weeks with one objective: putting the incoming Trump administration on notice.

“It’s a warning shot to the new administration that we won’t sit back, and we have leverage also in the event of a deepening of the trade tech wars,” said Myron Brilliant, a senior counselor at Dentons Global Advisors-ASG, a business consulting firm.

So far in the tit-for-tat between the world’s superpowers, Washington has set the tone for tough measures aimed at curbing China’s economic influence and stifling the development of industries that could give it a military edge.

In its final days, the Biden administration has issued new rules to restrict Chinese access to semiconductors and imposed penalties on companies in mining, real estate, solar energy and shipping. Some observers termed it “China sanctions week.”