BEIJING (Reuters) - China said on Friday that the United States should tell its airlines to change their websites to refer to self-ruled Taiwan as Chinese territory, after the United States said China had rejected requests for talks on the matter.

FILE PHOTO: A staff member walks past U.S. and Chinese flags placed for a joint news conference by U.S. Secretary of State Mike Pompeo and Chinese Foreign Minister Wang Yi at the Great Hall of the People in Beijing, China June 14, 2018. REUTERS/Jason Lee/File Photo

China has demanded that foreign firms, and airlines in particular, begin referring to Taiwan as Chinese territory on their websites, along with Hong Kong and Macau, a move described by the White House in May as “Orwellian nonsense”.

Numerous non-U.S. carriers, such as Air Canada AC.TO, Lufthansa LHAG.DE and British Airways ICAG.L have already made changes to their websites, according to Reuters checks.

But several U.S. companies, including Delta Air Lines DAL.N and United Airlines UAL.N, were among carriers that sought extensions to a May 25 deadline to make the changes. The final deadline is July 25.

Speaking at a daily news briefing, Chinese Foreign Ministry spokesman Lu Kang said it was the broad consensus in the international community that there was only one China and that Taiwan was part of it, and that this was not up for negotiation.

Foreign companies operating in China must respect the country’s sovereignty and territorial integrity as well as the feelings of the Chinese people, he added.

“I again stress, the ‘one China’ principle is the political basis of Sino-U.S. ties, and brooks no negotiations or consultations,” Lu said.

“The U.S. government should urge the relevant companies to scrupulously abide by the one China principle and rectify their websites as soon as possible.”

China has rejected U.S. requests for talks over how American airlines and their websites refer to Taiwan, according to sources, adding to tensions in a relationship already frayed by a major trade dispute.

The United States switched diplomatic recognition from Taiwan to China in 1979, acknowledging that China takes the position that there is one China and Taiwan is part of it. But the United States is also Taiwan’s biggest ally and arms supplier.

Taiwan is China’s most sensitive territorial issue. Beijing considers the self-ruled, democratic island a wayward province. Hong Kong, a British colony for more than 150 years until 1997, and neighboring Macau, administered by Portugal for centuries until 1999, are part of China but are run largely autonomously.