WASHINGTON - The United States Centres for Disease Control and Prevention (CDC) is working with Singapore's Ministry of Health regarding the country's Covid-19 testing data, the US agency told Bloomberg News on Thursday (Jan 6).

The CDC will also update its Travel Health Notice for Singapore accordingly.

The move comes days after the CDC earlier this week reclassified its Covid-19 advisory for Singapore and said the situation in the country was "unknown".

At issue was a lack of testing findings, which the CDC previously obtained from aggregator Our World in Data, according to a separate statement from the CDC to Bloomberg at the time.

As a result, the CDC warned that "even fully vaccinated travellers may be at risk for getting and spreading Covid-19 variants".

That put Singapore in the company of Afghanistan, North Korea and Syria under a category of destinations which Americans are told to avoid because of high infections.

The CDC's designation surprised officials in Singapore, which maintains far stricter testing and social distancing measures than the US, and its Ministry of Health posts detailed virus statistics in English online every day.

In response, Singapore said it would share its Covid-19 statistics with the CDC and the local US embassy.

"Just to be clear, we know our situation very well," Health Minister Ong Ye Kung told reporters on Wednesday.

Mr Ong noted that more than 150,000 polymerase chain reaction (PCR) tests are administered weekly, which work out to more than 21,000 such tests daily. Positive rates for these tests are under 2 per cent, he said.

Singapore has 145 wastewater testing stations across the island, including in housing estates, dormitories and nursing homes.

"Only a very small handful are registering the presence of Covid-19 viral fragments," Mr Ong added. "So we are sure that the incidence of Covid-19 in our community is currently low and stable," he said.