Prime Minister John Key says he is waiting to hear if last night's earthquake caused significant damage but is pleased that no one seems to have been hurt.
Mr Key is visiting Invercargill on a scheduled trip today but said he was happy to visit quake affected areas if required.
The 7.8 magnitude quake was felt widely throughout the South Island and as far north as Taranaki, but no major damage has been reported, though there were some temporary power outages in the south.
The quake struck at 9.22pm, 100km northwest of Tuatapere, and was followed by strong aftershocks of 6.1 and 5.9.
"If there is significant damage or something that I can usefully be deployed to I will certainly go and have a look and lend a hand," Mr Key told Radio New Zealand.
Any government response would depend on damage which had yet to be assessed.
"All the feedback we've had so far is while it's been a large quake, certainly at this point no reported loss of life which is fantastic, and no great reports of damage."
