Chinese hospitals and funeral homes were under intense pressure on Wednesday (December 28) as a surging COVID-19 wave drained resources.
The scale of the outbreak and doubts over official data prompted some countries to consider new travel rules on Chinese visitors.
In an abrupt change of policy, China this month began dismantling the world's strictest COVID regime of lockdowns and extensive testing, putting its battered economy on course for a complete re-opening next year.
The lifting of restrictions came after widespread protests against them.
Some international health experts say this means COVID is spreading largely unchecked, and could be infecting millions of people a day.
China's foreign ministry on Wednesday said there should be a scientific basis for implementing COVID-19 rules after the United States government announced it may impose new measures for travellers from China.
U.S. officials made the announcement on Tuesday over concerns over a "lack of transparent data" coming from Beijing.
Japan has said that from Dec. 31 it will require a negative COVID-19 test upon arrival for travellers from mainland China, while Taiwan will test arrivals from China from Jan. 1.
Italy has also said it will also impose mandatory testing for travellers from China.
In a major step towards freer travel, China will stop requiring inbound travelers to go into quarantine from Jan. 8, authorities said this week.
The global financial hub of Hong Kong also said on Wednesday it would scrap most of its last remaining COVID restrictions.
The speed at which China, the last major country in the world moving towards treating the virus as endemic, has scrapped COVID rules has left its fragile health system overwhelmed.
China reported three new COVID-related deaths for Tuesday, up from one for Monday
These numbers are inconsistent with what funeral parlors are reporting, as well as with the experience of much less populous countries after they re-opened.