Prime Minister Bill English says some of Civil Defence's decisions around the Port Hills fire "could have been made better".
However, he told Morning Report today local authorities faced an "unprecedented situation" for New Zealand and Christchurch.
Mr English said he sympathised with Christchurch Mayor Lianne Dalziel.
"Because of their experience [with the earthquakes] they are pretty capable with these decisions, but as Minister [Gerry] Brownlee has pointed out, maybe some of them could have been made better."
Mr Brownlee, who Civil Defence Minister, criticised the local authorities for failing to declare a state of emergency earlier.
"You always know what Gerry [Brownlee] thinks. The issue is on the table," Mr English said.
Civil Defence had a tension between centralised control and local knowledge, Mr English said.
"There's bound to be some disagreements about some decisions that were made under pressure.
"The aim is for people to have confidence in the system," he said.
Things were "very tense" on Tuesday and Wednesday because of the fire conditions.
"We'll have time to consider whether the right set of decisions were made."
English also spoke to Morning Report on other matters
- On Scott Brown potentially becoming the US ambassador to New Zealand: "It was the United States' decision."
- On reviving the TPP trade deal: The US was a stabilising influence in the Asia-Pacific. Many countries decided to sign up to the TPP thinking the US would be part of it, he said.
- On Australian Prime Minister Malcolm Turnbull rejecting New Zealand's offer to take 150 refugees from Australia's off-shore detention camps: The main focus for Australia was on the refugee deal with the US.
- On the potential for National to offer New Zealand First leader Winston Peters the deputy prime minister role post-election: "We won't be spending the next few months courting Winston Peters."
The relationship between the two countries was in "good shape" and New Zealand wanted an ambassador who understood that, Mr English said.
"The [New Zealand] offer remains, it doesn't look likely to me they will take it up in a hurry."
"The only thing we'd rule out would be sharing the Prime Minister's job."