The US has become the latest country to impose Covid testing on visitors from China, after Beijing announced it would reopen borders next week.
After three years of being closed to the world, China will let people travel more freely from 8 January.
But the country's ongoing Covid surge has sparked wariness.
China is reporting about 5,000 cases a day, but analysts say such numbers are vastly undercounted - and the daily case load may be closer to a million. Hospitals are overwhelmed and residents are struggling to find basic medicines, according to reports.
On Wednesday, the US said a lack of "adequate and transparent" Covid data in China had contributed to the decision to require Covid tests from 5 January for travellers entering the country from China, Hong Kong and Macau.