Dunedin International Airport manager John McCall said the reclassification idea had been "on the agenda for a number of years" and he supported the move.
"Airports are all in favour of making travel across the Tasman easier," Mr McCall said.
Issues surrounding duty-free, security, immigration and biosecurity would have to be agreed upon before the routes changed from international to domestic, he said.
"There has to be a lot of work, but we welcome it," Mr McCall said.
Airlines spoken to yesterday supported the move as it would help reduce extra costs such as airport service charges, effectively reducing the price of a ticket by more than 20%, and speed up processing flights.
Pacific Blue spokesman Phil Boeyen said the airline supported any move that would lower fares and encourage more people to fly transtasman.
Air New Zealand had been trialling special kiosks at Auckland International Airport since late last year, and they "had gone very well", a spokesman said.
Australia and New Zealand passengers made up the bulk of transtasman passengers.
Other foreign nationals would still be classed as international visitors, requiring visa and customs checks.
Last week, Jetstar chief executive Bruce Buchanan called for a common border between the two countries after launching the airline's domestic service.
The issue of a common border had been discussed between Australian and New Zealand customs officials for several years, and was still years away, a Customs spokesman said.
Customs Minister Maurice Williamson told the Otago Daily Times he supported any move that would "facilitate the movement of passengers between the two countries".
Calls to Mr Williamson were not returned yesterday.
Tourism Minister, Prime Minister John Key declined to comment on the issue until he had been briefed by Mr Williamson.
