WASHINGTON /SYDNEY (Financial Times) -- The Trump administration has urged United Airlines and other U.S. carriers to ignore Chinese demands over how they refer to Taiwan, in the latest example of mounting friction between the U.S. and China.

US officials have asked United, American Airlines and Delta not to comply with a Chinese demand to write "Taiwan, China" instead of Taiwan on their websites and maps, according to five people familiar with the issue. The request came after China ordered 36 foreign airlines to remove any language which implied that Taiwan, a democratically ruled independent island claimed by Beijing, was not part of China.

The White House last month described the Chinese order as "Orwellian nonsense". Trump administration officials have urged the airlines to push back and to tell China, which has extended the deadline until late June, that the Taiwan issue should be handled by the U.S. and Chinese governments.

American Airlines declined to comment on the specifics of discussions with the government. But Doug Parker, its chief executive, last week told the Financial Times that the Taiwan issue was "between countries".

"The United States has replied to the Chinese government and as a result we are following the direction of the U.S. government," said Mr Parker, who would not say if he viewed the order as Orwellian nonsense. "I'm not certain if we are obliged to [heed the US government guidance] but right now it is between our government and their government and we are following the guidance of our government."

One person familiar with the talks between the U.S. and the airlines said one top official had discussed the issue with Oscar Munoz, United's chief executive. Several people said the National Security Council had been unusually involved in the talks with the airlines, but a White House spokesperson denied that assertion.

United declined to comment. Delta said it was reviewing the Chinese request and would "remain in close consultation with the U.S. government."

While the White House argues that it can help provide cover for the U.S. carriers, the Chinese threat poses a big problem for the airlines since they could lose landing spots in China for not complying. It also comes as the Chinese market becomes increasingly important for the global aviation market.

"If airlines are denied landing rights, they will simply have to deal with the commercial realities presented by the Chinese government and U.S. top cover won't help," said Evan Medeiros, a former White House Asia official. "The only message the Chinese will understand is if the airlines, for their own reasons, are not willing to accept Chinese demands. The Chinese know the pressure points, and it is airline operations and not government-to-government interactions."

Qantas this week became the latest foreign airline to say it would comply with the Chinese order, despite reservations from Julie Bishop, Australia's foreign minister, who said companies "should be free to conduct their usual business operations free from political pressure". Alan Joyce, chief executive of Qantas, said the Australian carrier would "meet the requirements" but it was "just taking time to get there".

The Taiwan spat comes as Sino-U.S. relations have become more tense on many fronts, including the much publicised trade friction to US concerns about the militarisation of the South China Sea. China has expressed anger at Congressional moves to promote more visits by U.S. officials to Taiwan, and is concerned that the Trump administration has several senior officials with strong pro-Taiwan views, including John Bolton, the national security adviser who has long been an ardent supporter of Taipei.

The Chinese pressure over the way companies describe Taiwan has extended to several industries, including hotel chains such as Marriott and retailers such as Zara. Two people familiar with the reaction inside the White House said officials were angry when Delta earlier this year apologised to China for listing Taiwan - and Tibet - as countries on their website.

One of the two people said the U.S. airlines were willing to comply with the Chinese order after a period of time. But he said the Trump administration seemed intent on fighting China over the issue regardless of the views of the U.S. carriers who are eyeing future growth opportunities in the Chinese market.

A bipartisan group of US senators, including Cory Gardner from Colorado and Marco Rubio from Florida, ​recently wrote to United and American to urge them to resist the "long arm" of the Chinese government. Mr Gardner told the Financial Times that the airlines should think twice about complying with the Chinese order, and said the US should consider retaliatory measures again Chinese airlines if necessary.

"The American airlines ought to be . . . representing the interests of this country. If China wants to cancel flights because of bullying tactics, the U.S. should reciprocate," Mr Gardner said. "If a U.S. airline wishes to capitulate to the demands of China, perhaps they would rather do business headquartered out of China."