Beijing did not really have the option of responding dollar for dollar because China simply does not buy that much from the United States. China sells goods each year to the United States worth nearly four times as much as it buys.



But Chinese officials have suggested in recent weeks that if the United States proceeds with tariffs on a very wide range of Chinese goods, then Beijing may also retaliate against the Chinese-owned operations of big American companies. From Apple to General Motors, a long list of large American enterprises have transferred extensive operations to China and could be vulnerable to any response from Beijing.

The iPhones, Chevrolets and other products manufactured and sold in China by American companies are mostly designed in the United States, and the Trump administration has declared various Chinese industries to be threatening American national security, illegally copying foreign intellectual property or causing widespread job losses in the United States. China has denied violating international trade norms.

China’s latest threat on trade came at the end of a day during which Beijing also allowed its currency, the renminbi, to slide further against the dollar in foreign exchange markets. The currency is allowed to trade in a daily range set by the central bank.

China’s central bank has now let the currency slip almost 9 percent since mid-April, when it took less than 6.3 renminbi to buy a dollar. A weaker renminbi makes Chinese exports more competitive in foreign markets, while making imported goods more expensive within China. Government advisers and analysts have said that the government is not deliberately driving the currency down against the dollar to derive a trade advantage, but is being led instead by traders in currency markets, who are increasingly worried about China’s slowing economy and huge debt burden.

By adding the option of 25 percent tariffs, however, the Trump administration would have an extra weapon in case the renminbi falls further and gives Chinese exporters an added advantage.