Christopher Luxon says he has "full support" of his party, after a vote of confidence 12 weeks before a general election.
The storm lashed the Mariana Islands, hitting Rota and prompting emergency warnings on Guam.
The test launch came hours after Australia signed a new defence pact with its Pacific island neighbour Fiji.
Tuna populations around the Pacific Islands could move away as ocean temperatures increase.
The rise in energy prices has hit Asia particularly hard as many nations are heavily reliant on Gulf oil.
Police say they are not expecting to find any more survivors from the landslide, with six people still unaccounted for.
The search continues for missing people after a landslide hit a popular campsite in Mount Maunganui.
Vijay Kumar's family say they are "trying to cope with this harsh reality" following his death.
The small South Pacific nation is facing one of the world's fastest growing HIV epidemics.
