An airport employee (right) wearing a face shield checks a passenger's body temperature at the Indira Gandhi International Airport in New Delhi, India, May 25, 2020. (Photo by Partha Sarkar/Xinhua)

Tighter epidemic preventative rules, including negative nucleic acid test results and health status checks will be required for all travelers departing from India to China, starting from September 14, according to a notice issued by the China's Embassy to India on Sunday.

To ensure the health and safety of international travelers and reduce the risk of cross-border coronavirus transmission, all nucleic acid tests must be taken three days prior to departure. Passengers should have their tests taken in any designated hospitals or laboratories authorized by the local government, and no other form apart from the nucleic acid test are acceptable, reads the notice. 

Chinese nationals will need to acquire the green health code with "HS" label generated from the negative nucleic acid test results to board the flight, and foreign travelers are required to submit health status declarations provided by the Chinese embassy before boarding, according to the notice. 

It also specifies that the local government currently does not allow transiting flights to China via India, and local airports do not have nucleic acid testing facilities. 

For travelers departing from India and transiting in a third country to China, the green health codes with "HS" label or health status declarations are also needed as a double check, and if the documents fail to meet standards, travelers might be prevented from boarding transiting flights. 

Flights from the US have also adopted tighter rules starting from September 15, according to an announcement by the Chinese embassy in Washington on Friday, specifying that all passengers departing from the US to China will have to provide negative coronavirus test results taken within three days, rather than the previous two weeks, and submit their health codes or declarations before boarding. 

On July 20, the Civil Aviation Administration, the General Administration of Customs, and the Ministry of Foreign Affairs jointly issued a list of countries that have also adopted stricter coronavirus testing measures for travel or transiting to China. The list covers 82 countries including Russia, the UK, Germany, and Singapore.

Flights from the US to China doubled in September, United Airlines told the Global Times on Sunday, noting that starting Friday, the airline has increased flights between San Francisco and Shanghai from two to four a week.