KEY POINTS:
From today, New Zealanders travelling to, or through, the United States will have to apply online for approval before they can enter the country.
The Electronic System for Travel Authorisation (ESTA), which has been applicable since August last year, becomes compulsory for New Zealand, Australia and some European and Asian countries today.
New Zealanders are currently exempt from visa requirements to enter the US for short visits, including transit, under the Visa Waiver Programme.
However, instead of filling out paper waiver cards on the plane, travellers must apply online at https://esta.cbp.dhs.gov (the US Embassy website also provides a link to this address) for approval.
American authorities says travellers should apply at least 72 hours before departure. The details they will be asked to disclose will be the same as that asked on the US immigration declaration cards which are handed out on the plane, including passport number, country of residence, disclosure of communicable diseases and any involvement in terror activities.
Once a traveller is approved, the information will remain valid for two years and he or she will be allowed to make multiple trips during the period.
The application is free, but the US Government said it reserved the right to charge a fee in future. The US Department of Homeland Security said the new system was part of its security measures after the September 11, 2001, terror attacks.
But it has come under strong criticism in New Zealand since the rule was announced without warning last year.
Green Party human rights spokesman Keith Locke called it "anti-terrorist paranoia" and Travel Agents Association president Peter Barlow said it was "another compelling reason not to go via the States".
* Flying to the USA?
Go to https://esta.cbp.dhs.gov at least three days before you leave NZ.
Fill out the online immigration form on the site.