• Japan and some other countries have announced new rules for visitors from mainland China after Beijing said it would finally relax border controls.
• Covid-19 infections surged this month in mainland China, but there is limited data available publicly.
• Australia is not adding restrictions on visitors from China, Prime Minister Anthony Albanese said Thursday.

BEIJING — Some countries announced new Covid testing requirements for visitors from China after the mainland said it would finally relax border controls.

Japan was the first country to subsequently release rule changes, followed by the U.S. and others. Covid-19 infections surged this month in mainland China, but there is limited data available publicly.

Here are some of the latest policy changes for travelers from China:

South Korea

Starting Jan. 2, all visitors to South Korea until the end of the month will need to show a negative Covid test before boarding flights to the country, Prime Minister Han Duck-soo said Friday. He said travelers will also need to test for Covid upon arrival in South Korea.

It was unclear what would happen to travelers who tested positive after arriving.

"The South Korean government feels the need to take action in order to prevent further domestic spread of Covid as we see a worsening situation taking place in China as the nation eases its restrictions," Han said in Korean, according to a CNBC translation.

The country will only allow flights from China to land in Incheon and will temporarily halt plans to increase the number of flights from China, Han said.

Japan

Beginning Friday, all travelers from mainland China will need to test for Covid-19 upon arrival in Japan, according to the health ministry.

Those who test positive will need to quarantine at a designated facility, the ministry said. Multiple media reports said the isolation period was seven days.

The new rules also apply to people who visited mainland China within the seven days prior to arrival in Japan, the health ministry said. But travelers from Hong Kong or Macao are exempt.

U.S.

Starting Jan. 5, all airline passengers 2 years and older originating from mainland China, Hong Kong or Macao will be required upon departure to the U.S. to show a negative Covid-19 test result from within the last two days, the Centers for Disease Control and Prevention announced Wednesday.

The rules apply to people of all nationalities and vaccination status.

Testing has decreased across China and it's unclear what variants are circulating on the mainland because genomic surveillance data is also limited, a federal health official told reporters.

Taiwan

For the month of January, all travelers from mainland China via direct flight or boat will need to test for Covid-19 upon arrival in Taiwan, the local Centers for Disease Control said Wednesday.

Those who test positive can quarantine at home, the notice said.

The rules do not apply to flights from Hong Kong or Macao.

Italy

All travelers coming from China to Italy will need to get tested for Covid-19, even if just transiting, the European country's health minister said Wednesday.

The minister said the country would also conduct virus sequencing, but did not say what would happen to travelers who tested positive.

Health authorities in regions near Milan and Rome said travelers who tested positive would have to quarantine in designated buildings, Reuters reported.

Australia

Australia is not adding restrictions to visitors from China, Prime Minister Anthony Albanese said Thursday, according to an official transcript of his interview with the Australian Broadcasting Corp.

Albanese said Australia would monitor circumstances in China and other countries, as well as take "appropriate advice" from health experts. "Our priority is to keep Australians as safe as possible," he said.

Omicron — more transmissible but causing less severe disease — became the dominant Covid variant globally over the last year. Most of the world moved to a state of living with the virus months before China ended many of its Covid controls this month.

Starting Jan. 8, inbound travelers to mainland China will no longer need to quarantine upon arrival, Beijing announced Monday. Visitors would still need to show a negative for Covid-19 from within the last 48 hours.

Chinese authorities also said they would improve visa processing for foreigners, while resuming Chinese citizens' passport applications for travel abroad, including for tourism. No exact timeframe was specified.

—CNBC's Jihye Lee and Spencer Kimball contributed to this report.