Air New Zealand is ramping up its regional services in the wake of Jetstar's withdrawal.

The airline will operate an additional 253 one-way flights in December on services it operates between Auckland and Napier, New Plymouth, Nelson and Palmerston North, as well as between Nelson and Wellington, adding more than 15,500 seats in the process.

Cam Wallace, Air New Zealand chief revenue officer, said the airline has been looking at ways to help support the routes affected by Jetstar's withdrawal from the regions.

"Air services are extremely important for regional New Zealand, particularly over the busy holiday period, so we're pleased to be able to step in and add capacity to the routes impacted."

Wallace said the airline was also looking at additional capacity on regional services post December.

Jetstar confirmed earlier this month that it would cease five regional services in New Zealand at the end of November.

Jetstar had been operating the affected routes for the past four years.

However, the airline has been unable to make money from these routes.

"As we explained when we announced our proposal in September, this decision is based on our regional operations continuing to be loss-making, combined with higher costs and a softening of the regional travel market," Gareth Evans, Jetstar's chief executive officer said.

The number of additional flights and seats on each route for December 2019 are as follows:
Auckland – Napier
Seats: 3,120
Flights: 48

Auckland – New Plymouth
Seats: 2,404
Flights: 38

Auckland – Nelson
Seats: 3,940
Flights: 59

Auckland – Palmerston North
Seats: 3,120
Flights: 48

Wellington – Nelson
Seats: 3,072
Flights: 60

Total additional seats: 15,656
Total additional flights: 253