Airline passengers to the United States will be isolated from other travellers at Auckland Airport and face a rigorous second set of security checks following the suspected terrorist attack on a Christmas Day flight to the US.
Passengers are being urged to check in early as the increased security is likely to add to waiting times.
The new rules are a worldwide directive imposed by America's Transportation Security Administration (TSA) for all flights to the US.
Auckland Airport staff had only six hours' notice of the change on Saturday before their next US-bound flight.
After the usual customs, immigration and security checks, travellers must have another series of checks.
Aviation Security Service general manager Mark Everitt said he was unable to comment on specifics, but the Herald understands the checks include rigorous luggage searches, the use of sniffer dogs and possibly body searches.
Screens have been put up in departure lounges so US-bound passengers cannot interact with other travellers.
The Aviation Security Service's northern regional manager, Peter Pilley, said passengers should allow an extra hour before the departure time for their flight.
He advised people to take as little carry-on luggage as possible to speed the process.
The TSA directive also says passengers must remain seated for the final hour of their US-bound flight and are not allowed access to carry-on baggage or to have any items on their laps.
Between 20 and 30 extra staff were called in yesterday to Auckland Airport to process passengers.
The security upgrade comes after a Nigerian man tried to destroy a plane flying from Amsterdam to Detroit on Friday.
Umar Farouk Abdulmutallab allegedly had explosives strapped to his body, but was overpowered by passengers and crew.
Abdulmutallab, who suffered extensive burns, has possible links to al Qaeda militants.
Mr Everitt said New Zealand Government intelligence agencies had assessed the threat to aviation since the incident and concluded it was low.
"This is totally a US-driven requirement, not a New Zealand Government requirement," he said of the checks.
The TSA would in the next few days decide whether the rules would stay in force in New Zealand.
Mr Everitt said the TSA would have to consider that New Zealand was a low threat, that aircraft going from it to America were carrying New Zealand, Australian or American citizens who were a low threat, and that aviation security in New Zealand was recognised as being of a high standard.
Air New Zealand and Qantas are the only airlines with flights from New Zealand to the US.
Air New Zealand refused to comment, but Qantas confirmed that all passengers have to stay seated for the last hour of their flight.
Spokeswoman Olivia Wirth said travellers would go through thorough security checks before boarding.
"We have asked passengers to arrive at the airport in plenty of time for check-in to assist us in getting away on time."
Air New Zealand has about 21 flights a week to the US, landing in Los Angeles or San Francisco.
Qantas has 43 return flights a week between Australia and the US, including seven from Melbourne that go through Auckland to Los Angeles.