Several international airlines still listed Taiwan as a separate country on their websites on Friday despite a deadline set by Beijing for carriers to refer to the self-governed island as a Chinese territory.
Chinese Civil Aviation Administration sent a notice to 36 foreign airlines last month, asking them to comply with Beijing's standards of referring to Taiwan, Hong Kong and Macau as Chinese territories, in a move described by the White House as "Orwellian nonsense."
According to a copy of the letter circulating on Chinese social media, it was dated April 25 and gave carriers 30 days to comply, indicating a deadline of May 25. AFP could not verify the authenticity of the document.
But AFP found at least eight foreign airlines were still listing Taiwan as a country on their websites as of Friday, including United, American Airlines, Cathay Pacific, All Nippon Airways and Qantas.
A spokesperson for Qantas told AFP that Chinese authorities have given the Australian carrier "additional time to further clarify how we refer to Chinese territories".
Around a dozen other airlines including Air Canada, Air France, British Airways and Germany's Lufthansa list Taiwan as a Chinese territory, though it is unclear when they started referring to the island that way.
The Taiwanese foreign ministry last week requested Air Canada for a "speedy correction" after the carrier made the changes.
China's Civil Aviation administration declined to comment on when the deadline was or how many airlines have complied with their request.
The letter did not clarify the punishment for non-compliance, only saying it would be deemed as "serious discreditable conduct".
China sees democratic Taiwan -- which has never formally declared independence from the mainland -- as a renegade part of its territory to be brought back into the fold, by force if necessary.
Meanwhile, Hong Kong, a British colony until 1997, and Macau, a Portuguese colony until 1999, are now "special administrative regions" of China.
Beijing has become increasingly sensitive to how foreign firms describe them, pressuring numerous international brands in recent months to amend language perceived as slights to its national sovereignty.
US retailer Gap Inc. apologised last week for selling a T-shirt which it said had an "incomplete map" of China.
Japanese retailer Muji was fined 200,000 yuan ($31,000) for packaging that identified Taiwan as a separate country, Shanghai's administration for industry and commerce said last month.
Washington has maintained a delicate diplomatic balance since 1979, recognising Beijing's sovereignty as part of its "One China" policy, while remaining Taiwan's most powerful unofficial ally and main weapons supplier.