The US has become the latest country to impose mandatory Covid tests on Chinese tourists, after China announced it would reopen its borders next week.
Tighter measures have also been brought in by Italy, Japan, Malaysia, Taiwan and India.
After almost three years of restrictions, China will let people travel more easily from 8 January.
At the same time, the country is facing a surge in Covid cases, leading to wariness among some countries.
However, Beijing said coronavirus rules should be brought in on a “scientific” basis, and accused some countries and media of “hyping up” the situation.
On Monday and Tuesday, China announced it would ease its restrictions on travel to and from the country.
Travel sites reported a spike in traffic following the announcements – and some countries revised their travel rules.
The US said that from 5 January all passengers travelling from China, Hong Kong and Macau would need a negative Covid test to enter the country in order to “slow the spread” of the virus.