They also voted to establish a project control group with councillors Greg Martin, Phil Halse and Cherry Hermon at the helm.
The decision comes after the Whangarei Airport Strategic Study found issues with the current site in Onerahi, including problems associated with Civil Aviation rules and runway length.
At 1098m long, Onerahi's sealed runway is the shortest commercial runway in New Zealand, with a Runway In Safety Area (RISA) in the "tens of metres", said Mr Weston.
The national minimum and recommended RISA lengths are 90m and 240m respectively, and the ideal length of the sealed part of the runway would be around 1350 to 1500m - making the ideal total runway around 2000m.
An international airport would require a sealed runway of over 1800m.
The cost of expanding the current runway is estimated at $140 million, thanks to the shipping channel at one end, and the Waikaraka Hills at the other, Mr Weston said.
Port Nikau was originally touted as a potential in stage one but the study found it would cost about $148 million to establish an airport there.
"There were significant costs to do with poor ground conditions and the reclaiming of the land," Mr Weston said.
The ideal piece of (flat) land for a new airport would be around 50 hectares with no terrain limitations such as hills, good bearing capacity (solid ground), and a good orientation to the prevailing wind, with minimal fog.
Public consultation will begin as part of the long-term plan process in March next year, with funding being made available for stage two by July 2015.
Councillors also voted to commence short-term upgrades to the existing airport, including expanding the terminal, refurbishing internal areas and toilets and expanding the baggage handling area, at a cost of $1.02 million.