Major US airlines appear to be making concessions towards China's demand that they refer to Taiwan as part of China in their flight schedules, with American Airlines and Hawaiian Airlines making changes to their websites ahead of Beijing's Wednesday deadline.

At least three unnamed sources told Reuters and Bloomberg that Delta and United Continental would also make changes, after coordination between the carriers and the US government.

Beijing has demanded that foreign firms, and airlines in particular, not refer to Taiwan as anything other than a Chinese territory on their websites, a move described by the White House in May as "Orwellian nonsense".

The US carriers would change the Taiwan references soon, said one person, who asked not to be named on Tuesday because discussions among the carriers were private. Later on Tuesday, Hawaiian Airlines had removed mention of "Taiwan" from its schedules. By Wednesday morning, American had followed suit.

On Tuesday night, the American Airlines website was referring to "Taipei, Taipei Taoyuan Airport (TPE), Taiwan". On Wednesday morning, the same search produced "Taipei Taoyuan Airport (TPE)".

The four airlines had been hoping for a negotiated resolution between the US and Chinese governments ahead of China's Wednesday deadline.

"We're a business with significant international activities and we need to deal with regulations in all of those jurisdictions," Peter Ingram, Hawaiian's chief executive officer, told Reuters on Tuesday. "And obviously sometimes that can put us in challenging positions in one jurisdiction versus another."

Hawaiian consulted with its US peers and government officials in both the US and China before deciding to make adjustments, Ingram said. The company doesn't fly to Taiwan itself but does sell tickets through a code-share relationship with China Airlines, which flies nonstop from Taipei to Honolulu. Hawaiian also operates its own service to Beijing.

American, Delta and United declined to comment.

Numerous non-US airlines including Air Canada, Lufthansa, British Airways, Qantas, Air France-KLM and Deutsche Lufthansa AG have already made changes to their websites, after China's Civil Aviation Administration sent a letter to foreign air carriers earlier in the year.

The carriers were told to remove references on their websites and other materials that suggest Taiwan, Hong Kong and Macau are part of countries independent from China, but several US operators, including Delta Air Lines and United Airlines, had requested more time to handle the matter.

The 44 foreign airlines cited by China's civil aviation authority for their labelling of Taiwan have taken different steps to assuage Beijing.

Japan Airlines has been creative: customers now choose "city and language" on the airline's website landing page, instead of "region and language", with Hong Kong, Taipei and Beijing listed under "East Asia" on the booking page. Korean Air and Asiana Airlines now list destinations by city and airport.

A US airline executive briefed on the issue told Reuters that the US State Department notified China's embassy in Washington late on Monday of the decision by US airlines to only list certain destinations by city on both Chinese and English websites, and not refer to Taiwan as a jurisdiction.

Another source in Beijing told Reuters he was informed unofficially by the US government that airlines would only use certain city names in the future.

A senior US government official said the change was ultimately the airlines' choice to make.

Searches on the websites of Delta and United still mentioned Taipei as being in Taiwan.

Airlines for America (A4A), a trade group representing United, American, and other major carriers, acknowledged that changes were being made.

"As with other sectors of the economy, the US airline industry is a global business that must contend with a host of regulations and requirements," it said in a statement.

"A4A and the affected US airlines appreciate the engagement and counsel we have received from the Administration as carriers begin to implement a solution," it said.

The airlines were expected to make changes by the end of Wednesday in China.

"We have told China that the United States strongly objects to China's attempts to compel private firms to use specific language of a political nature in their publicly available content. We continue to seek to address this issue," a US embassy spokesman said.

It was unclear how China might punish airlines that do not comply, but in December it added a clause to rules governing foreign airlines in the country, saying regulators could change a company's permit if it did not meet "the demand of public interest".

"The 'one China' principle brooks no negotiations or consultations," Chinese Foreign Ministry spokesman Geng Shuang told a regular news briefing on Tuesday.

"We hope the US government urges relevant companies to strictly abide by the 'one China' principle and make changes to their websites as soon as possible," Geng said, adding that the deadline was fast approaching and everyone should "wait and see" what would happen.