Three members of the Prime Minister's trade delegation have tested positive for Covid-19 in Singapore, however the infections are believed to be historical.
The PCR test results will prevent the trio from travelling with the delegation to Japan on Wednesday, as the country requires negative Covid-19 tests to enter.
Compared to rapid antigen tests, PCR tests are more sensitive to historical infections and can still return positive results for weeks or even months after the virus has passed.
Jacinda Ardern arrived in Singapore on Monday and is spending two days in the city-state before flying to Japan.
In a press conference on Tuesday afternoon Ardern said she has recorded a negative PCR test and will travel to Tokyo.
There are 50 people that are part of the Government's trade delegation. The trip is Jacinda Ardern's first overseas trip since early 2020.
The Prime Minister is travelling with a 12-person business contingent including executives from Fonterra, Auckland Airport and Zespri.