The trip is being billed as a stopover as part of a Pacific tour, but comes amid long-running tensions between the US and China and growing concerns about the possibility of conflict over Taiwan.
After arriving in Hawaii, Lai said war would have “no winners” and that “we have to fight together to prevent war”.
China’s foreign ministry said it “strongly condemns” the visit and that it had “lodged serious protests with the US”.
The US has long maintained a deliberately ambiguous policy towards the island, declining to recognise its independence but maintaining informal relations with its government.
Speaking before his departure for Hawaii, Lai said the trip marked “the beginning of a new era of value-based diplomacy”.
