The government is being chastised for not following expert health advice when enacting a new COVID-19 testing measure for travellers from China.

The health minister and treasurer maintain the move was done out of "an abundance of caution" and to gather more data about COVID given Beijing's lack of transparency despite the chief medical officer advising against it.

Opposition health spokeswoman Anne Ruston said the government's inference the chief medical officer didn't provide cautious advice undermines the trust Australians have in lifesaving health advice throughout the pandemic.

"Right the way through the pandemic, Australians have been provided the confidence that the Australian government was responding to the best available advice of Australia's chief medical experts," she told AAP.

"Until now."

Senator Ruston also questioned how Australia would receive more data from tests being undertaken in China.

"The current arrangements for pre-flight testing will not result in any additional data on new or emerging COVID variants, because the tests will not provide Australia with any genomic sequencing," she said.

She called on the prime minister to be more transparent about why the health advice was ignored and whether future recommendations from experts would be followed.

Treasurer Jim Chalmers said the health advice had been taken seriously, with statements from the World Health Organisation raising concerns about China's transparency also considered.

"Our job in government is to make a decision which balances all the various factors and considerations. That's what we've done here," he told ABC radio.

"It's consistent with what a lot of countries are doing and it's erring on the side of caution."

Travellers from China will need to return a negative COVID test within 48 hours of departure from Thursday.

China criticised the measures, threatening to retaliate with reciprocal measures.

But details of the measures remain unclear, with China already requiring a negative test within 48 hours of departure and travellers only able to board a flight with a negative result.

China is fighting a nationwide outbreak of the coronavirus after abruptly easing restrictions that were in place for much of the pandemic.

Foreign Ministry spokesperson Mao Ning said the entry restrictions targeting China lacked scientific bases.

"We are firmly opposed to attempts to manipulate the COVID measures for political purposes and will take countermeasures based on the principle of reciprocity," she said.

Dr Chalmers says he's not particularly concerned about the threat.

"Not especially," he said when asked if the threat of retaliation worried him.

"We do need to make sure that we've got the best possible surveillance of strains as they emerge but also waves as they emerge and become more difficult to manage.

"That's really one of the key considerations here as we put these responsible restrictions in place."

Dr Chalmers added that the requirement to have a medical practitioner supervise a rapid antigen test wasn't an onerous one for travellers despite China's hospital system facing immense strain.