BEIJING (AP) — China says there will be “no room for negotiation” in its demand that U.S. airlines describe self-ruled Taiwan as part of China ahead of a deadline this week.

Beijing has insisted that carriers change references to Taiwan on their websites to “Taiwan, China” by Wednesday. Taiwan separated from China amid civil war in 1949 but Beijing continues to claim it as its own territory and has used its economic clout to isolate the island.

Foreign Ministry spokesman Geng Shuang said Tuesday that China hopes the U.S. government will urge businesses to follow China’s requirements. He did not specify how China would punish defiant carriers, saying only that it will “wait and see.”

The White House has previously criticized the Chinese demand as “Orwellian nonsense.”

The spat has added strain to a bilateral relationship already roiled by intensifying economic disputes. President Donald Trump has said he is ready to raise U.S. tariffs on $500 billion worth of Chinese imports if necessary and accused China in a tweet last week of unfairly manipulating its currency.

Delta Air Lines and American Airlines are among the last major international carriers to still refer to Taiwan as its own region or country. Many others, including Air Canada, British Airways and Lufthansa, have begun referring to Taiwan as part of China to avoid penalties or potential boycotts.

An airline from the Micronesian nation of Palau said last week that it was forced to shut down due to a steep drop in tourists from China. Chinese officials last year reportedly instructed tourist agencies to stop booking trips to Palau to punish the tiny nation’s diplomatic ties with Taiwan.