Earthquake Recovery Minister Gerry Brownlee says Christchurch is a long way from coming out of a state of emergency, even though the post-earthquake operation has moved from rescue to recovery.
Civil Defence announced on Thursday that it does not expect any more survivors to be found in the rubble left by the 6.3 quake on 22 February.
The last known survivor was rescued on 23 February.
The focus is now on recovering as many bodies as possible, so that they can be returned to relatives. The official death toll stands at 163 but it is feared the final number will be about 220.
Mr Brownlee says teams have a lot of buildings to deconstruct and bodies to retrieve.
Once they can determine with confidence that there are no further human remains to recover, he says, widespread demolition will take place - and that has to happen under a state of emergency, because parts of the city need to be closed off during the work.
In the new phase, Mr Brownlee says teams will be changing the way they approach buildings using more heavy equipment.
However, he says they will still go about the recovery effort with the utmost respect for any human remains, alert to the small possibility that someone may have survived.
Mr Brownlee says a top priority is to get the cordon around the central city reduced as much as possible, but that depends on plans to demolish the listing Hotel Grand Chancellor and other tall buildings.
Civil Defence said on Friday evening the cordon will be reduced on Sunday and a 30km/h speed limit will be in place in those zones.
Police operation's focus unchanged
Superintendent Russell Gibson says the change in focus has made no difference to the police operation.
He says the only visible change is that the no-fly zone over central Christchurch - imposed so that rescuers could hear the cries of anyone trapped in the rubble - has been lifted.
Superintendent Gibson says staff are working as quickly and compassionately as they can to identify the victims and release their bodies to their families, and he is still hopeful that most of the deceased will be identified through their DNA.
He estimates the recovery operation will take many weeks.
Survivor upset rescue mission over
The last person to be rescued, Ann Bodkin, says she is devastated to hear the operation has turned from rescue to recovery.
Ms Bodkin, who was trapped for 25 hours in the Pyne Gould building, told Morning Report that the thought of TV images of people rescued from other earthquakes after 10 days kept her strong.
She is urging recovery teams to continue to take extra care in the hope they might find a survivor.
The brother of Donna Manning, who worked at Canterbury Television and is still missing, says there is no good time to make the grim decision to move from rescue to recovery.
Maurice Gardiner told Morning Report the situation is overwhelming at times but the family supports the decision of rescue experts.
