"We are focusing on maintaining good stocks of all essential medicines, equipment and critical products."
Twyford said the aviation support package ensured key air channels to international markets stayed open and that there was huge demand for air freight from both importers and exporters.
Air NZ usually relied on a mix of passenger and air freight revenue to maintain its operations, he said.
"That's why we agreed to provide variable top-up funding for international air freight movements to make sure the flights are financially viable."
The maximum the Government will pay is $50,000 per return flight, but it will usually be less.
But if the flight is carrying enough cargo to make it viable on its own, then the Government pays nothing, according to the Ministry of Transport.
The Government has identified the key international ports for the movement of high value exports and critical imports as:
• Sydney (and other Australian ports)
• Singapore
• Hong Kong
• Los Angeles
• Dubai (other Middle East ports)
• Shanghai (and other Chinese ports)
Twyford said he would soon make further announcements about more funding arrangements for New Zealand's aviation system.
The day-to-day arrangements with Air NZ are being managed by New Zealand Trade and Enterprise, which is also working with exporters and government agencies to ensure the right capacity is available at the right times, he said.
Air New Zealand general manager of cargo Rick Nelson said last week that the airline had introduced a number of innovative measures to keep Kiwi businesses connected to the world.
• Covid19.govt.nz: The Government's official Covid-19 advisory website
It was offering cargo customers a range of aircraft charter services covering every port on the network (excluding London). It can also provide customised options from North American markets through to Australia.