Defence Force helicopters have so far airlifted more than 130 people from the quake-hit town of Kaikura and a state of emergency now covers the entire Canterbury region of New Zealand.
The latest developments were announced by Sarah Stuart-Black, director of Civil Defence and Emergency Management, at a briefing in the Beehive bunker late on Tuesday.
"The local state of emergency was declared across the Canterbury region to mobilise the collective force of the region," she said.
"This supersedes the local states of emergency in Kaikoura and Hurunui."
Ms Stuart-Black said food and water supplies were being distributed to communities where they were most needed.
"By night they will be going door-to-door to check on households," she said.
"Over 130 people have been evacuated so far and we are ensuring that people impacted by the earthquake are cared for."
Earlier on Tuesday, Defence Minister and acting Civil Defence Minister Gerry Brownlee said the evacuees were taken to Christchurch where local authorities helped tourists make accommodation arrangements.
"The four New Zealand NH90 helicopters have been evacuating people and bringing in supplies on each flight," he said.
He said authorities had not yet confirmed the total number of people displaced by the magnitude 7.5 earthquake and subsequent landslides.
But "essential supplies such as water, food, diesel equipment and personnel and oxygen for the local hospital have all reached Kaikoura today", he said.
"At this stage, it's hoped the inland route to Kaikoura, from the south, through Waiau will be cleared and reopened by the weekend."
"This is heavily dependent on weather conditions ... and the magnitude and frequency of aftershocks."
"Cell phone and landline coverage in Kaikoura is improving and providers are co-ordinating well, but services are not yet at 100 per cent."
"USAR teams are on the ground in Waiau and Kaikoura and a further 10 police personnel have arrived in Kaikoura."
Meanwhile, an area of central Wellington has been cordoned off where an earthquake-damaged nine-storey building is at risk of collapsing.
People in other buildings around the area, including a church, Rugby House and the New Zealand Red Cross headquarters, have been evacuated as a precaution.
Mr Nally said police and firefighters were conducting an operation to seal off the area and further decisions would be make on Wednesday.
