He tried the beverage at a ceremony which featured chants and dancing.
Crowds cheered as Prince Harry sipped the kava, which is used to treat anxiety and stress in some countries but cannot be imported to the EU.
Harry and Meghan were then met by huge crowds of people at the Grand Pacific Hotel, where they waved from a balcony.
The pair's 16-day tour which will also take them to New Zealand, Tonga and return to Australia.
