A central North island region is scrapping its tsunami text alert system after about 400 people got the message three hours late.

The move by Horizons Regional Council, which covers from Horowhenua to Ruapehu, comes as the Government plans to review New Zealand's Civil Defence response to yesterday's tsunami warning after confusion.

The council's warning text: "Estimated wave East Cape and Mt Maunganui 1m-0922. Stay tuned to local media for more information," was delivered about 11.56am.

Emergency services manager Shane Bayley immediately cancelled the free text service run by OPTN after complaints.

"It's just not good enough," he told the Manawatu Standard.

The council sent an apologetic text about 12.30pm: "The performance of the OPTN system this morning was not satisfactory. We will be investigating."

Acting Prime Minister Bill English said the Government was "generally happy" with the civil defence response but a number of vital agencies received confused warnings or no information at all.

"There was, I gather, a bit of confusion which can happen when an unexpected event happens very fast," he said today.

"We will be looking back at how it was handled once the civil defence position winds right down."

Mr English said he was surprised that when people were warned they went to the beaches which meant staff had to be deployed to get them to go home.

The emergency response body has been criticised after local media and one airport were left in the dark yesterday.

Civil Defence issued a tsunami warning about an hour after the 8.3 magnitude quake off Samoa, which hit at 6.48am.

It downgraded it to a threat advisory shortly after 11am.

State broadcaster Radio New Zealand reported that a special phone hotline in its newsroom, specifically for civil defence emergencies, did not ring.

Immediate inquiries were met with an answerphone which recommended ringing after 8am.

Television NZ also reported problems about mixed messages from Civil Defence on its Breakfast programme.

"We are classifying a tsunami but we are classifying those at the moment as rumour, we haven't got them confirmed," Colin Feslier told the show, which contradicted what news reports were broadcasting at the time.

Mr Feslier continued to give vague responses when pressed, the broadcaster reported.

Wellington International Airport was also overlooked in the alert despite it being a lifeline utility, Radio New Zealand reported.

Organisations such as media, electricity and telecommunications entities are legally required to continue operating in an emergency.

Wellington Airport was not notified about the tsunami alerts and calls to the Ministry of Civil Defence and the local Emergency Management Office also drew blanks, said operations manager John Barnden.

Civil Defence Minister John Carter said the response was not good enough and a review would show that lessons could be learnt.

The network, from a local government perspective, did work well, but communications needed to be improved, he said.

In the regions it was largely up for regional civil defence controllers to set up and manage warnings in their areas.

Civil defence systems were continually improving and lessons learned, Mr Carter said.

"It's an imprecise art. It's an act of nature and we do our best, obviously not good enough and we will be responding to it.

"I think Civil Defence weren't as helpful as they could have been in communicating with the media in the early stages."

Reports that Wellington Airport was not warned were a concern and that had to be sorted out, he said.

In 2006 Civil Defence was criticised for being slow and poorly organised after its response to a potential tsunami.