A man pulls a trolley with goods past a bench shaped like a bomb and with a U.S. flag outside a store in Beijing on April 3, 2018. (AFP/Getty Wang Zhao)

BEIJING — The Chinese Foreign Ministry is not known for its sense of humor. But when the Trump administration announced plans for $50 billion in tariffs, it issued an unusual response.

On Tuesday, the White House warned that it plans to hit Chinese electronics, aerospace and machinery products with billions in fresh tariffs, the latest in what is shaping up to be a major conflict over trade. Many in the United States worry that protectionist measures threaten supply chains and could mean higher prices for American consumers.

China warned that U.S. tariffs will be met with comparable measures from Beijing. Tucked into the Chinese Embassy’s response to Tuesday news, between references to win-win cooperation and referrals to the World Trade Organization, was this understated bit of shade: “As the Chinese saying goes, it is only polite to reciprocate.”

For a country whose official communications lean heavily on bland rhetoric, the quiet quip reads like a late-night comedian’s zinger.

The statement went on to say it is “not conducive to the U.S. national interests, not conducive to China’s national interests, and not conducive to global economic interests.”

“The Chinese side will resort to the WTO dispute settlement mechanism and take corresponding measures of equal scale and strength against U.S. products in accordance with Chinese law.”

“Only polite to reciprocate” is unusually dark and direct. Unlike the U.S. president, who salts his speech with off-the-cuff remarks about foreign policy, Chinese officials don’t usually digress with clever comments.

For months now, that script has been filled with firm but measured warnings that China has no intention of bowing to pressure from President Trump.

Wei Jianguo, a former vice minister of commerce, said the key to understanding China’s response is “same proportion, same scale and same intensity.”

“That means we will retaliate with the same strength,” he said. “Whatever the total value of trade the United States targets, we will target the same amount. If it’s in the form of tariffs, we will do the same.”

In a note published Wednesday, WilmerHale, the law firm, predicted that action will come soon. “It is likely that China will take retaliatory action in response to the Section 301 tariffs, which could include the imposition of tariffs on U.S. products exported to China,” said the note.

The prospect of a tit-for-tat economic battle between the world’s two largest economies? Not funny at all.

Luna Lin in Beijing contributed.