The number of border control staff at Auckland and Christchurch international airports is being increased to ease passenger congestion.

Prime Minister Helen Clark said today an extra $5.75 million would be allocated this financial year, increasing to $7.7 million in future years, to help the airports handle passenger processing.

"Tourists, business visitors and travelling New Zealanders are experiencing unacceptable delays because of congestion at our main airports," Helen Clark said in a statement.

"It is important to New Zealand's image and reputation that we act against unreasonable delays."

She said the problem had grown as New Zealand experienced "extraordinary growth" in visitor arrivals.

"The increase in passenger numbers was highlighted last summer season when three new airlines started international services in New Zealand, and two years of projected growth occurred in one year," she said.

"Tourism is a success story, attracting 2.25 million international visitors a year ... that's why we need to have infrastructure in place which can process passengers in a more timely fashion, while still undertaking the checks and clearances which are essential to protecting New Zealand."

The new funding will provide:

* 96 more customs officers at Auckland International Airport, ensuring the 50 arrival and departure booths are fully staffed at peak times, including allowance for some off-schedule flights;

*Two new MAF X-ray machines and 17 new staff at Auckland;

*Nine extra customs officers at Christchurch, as well as five new MAF quarantine officers and a new MAF X-ray machine.

Helen Clark said congestion at both airports had been building for three years.

"Last summer 10 per cent of passengers arriving during peak periods queued more than one hour and 15 minutes at the customs primary processing point, the passport control desks," she said.

"Some waited considerably longer than that. This is not the sort of experience we want to subject travellers to after what, for many, has been a long and tiring flight."

Tourism New Zealand chief executive George Hickton said the new funding would have a significant impact on the first experience of visitors.

"It is vital that when they arrive they receive a warm welcome and complete arrival formalities as quickly and smoothly as possible," he said.

"The quality of service provided at the frontline by our customs and MAF officials can have a huge bearing on visitors' perceptions of New Zealand."