China has struck back at President Trump.

In a rapid fire series of policy announcements from Beijing on Friday evening, including 34 percent across-the-board tariffs, China showed that it has no intention of backing down in the trade war that Mr. Trump began this week with his own steep tariffs on imports from around the world.

China’s Finance Ministry said it will match Mr. Trump’s plan for 34 percent tariffs on goods from China with its own 34 percent tariff on imports from the United States.

Separately, China’s Ministry of Commerce said it was adding 11 American companies to its list of “unreliable entities,” essentially barring them from doing business in China or with Chinese companies. The ministry imposed a licensing system to restrict exports of seven rare earth elements that are mined and processed almost exclusively in China and are used in everything from electric cars to smart bombs.

The commerce ministry also announced it was beginning two trade investigations into American exports of medical imaging equipment — one of the few manufacturing categories in which the United States remains internationally competitive.

China’s General Administration of Customs said that it would halt chicken imports from five of America’s biggest exporters of agricultural commodities and sorghum imports from a sixth company.

The new tariffs will hit fewer goods than President Trump’s tariffs only because China sells far more to the United States than it buys. China bought $147.8 billion worth of American semiconductors, fossil fuels, agricultural goods and other products last year. It sold $426.9 billion worth of smartphones, furniture, toys and many other products to the United States.