The Civil Aviation Administration of China said on Friday that it is evaluating how the websites of four United States-based airlines refer to Taiwan.

On April 25, the administration demanded that 44 foreign airlines review their websites and apps and cease listing the Hong Kong and Macao special administrative regions and Taiwan as independent countries.

By the July 25 deadline, the 44 airlines had all made some changes and 40 of them had made the full changes demanded by China, but four airlines based in the US has not fully corrected how they referred to Taiwan on their booking websites, the CAAC said.

American, Delta, Hawaiian and United airlines submitted rectification reports to the CAAC on July 25, saying that they have started making corrections and asked the administration to check the websites in two weeks.

A check of the websites of American, Delta and United airlines on Friday showed only the airport code and city names of airports in Taiwan, without adding the name Taiwan behind them, but they didn't use the expression "Taiwan, China", as other foreign airlines did.

The website of Delta airlines showed in its listing of "country or region", the company listed Taiwan independently without adding "China" behind it the way it lists "Hong Kong, China".

In the country list of Hawaiian Airlines, Hong Kong is listed independently as a country from China.