Chinese regulators say four US airlines have failed to carry out an order to call self-ruled Taiwan as part of China on their websites.
The air regulator says 40 out of 44 foreign airlines met a Wednesday deadline to change their websites, an order Washington opposed. It says United Airlines, American Airlines, Delta Air Lines and Hawaiian Airlines have yet to finish the job but gave no indication what remained.
Some carriers such as British Airways switched to calling Taiwan's capital "Taipei, China." American carriers switched to using the city name with no country.
Taiwan and China separated in 1949 following a civil war on the mainland but Beijing claims the island as part of its territory. The communist government has used China's growing economic clout to isolate Taiwan internationally.