Economic Development Minister Phil Twyford described the fire at the SkyCity Auckland Convention Centre as a "significant setback" but said it was too early to know the extent of the damage.
A large fire broke out today at 1pm on the roof at the National Convention Centre building site in Auckland.
"It's early days but this is a major fire, I understand firetrucks and firefighters have come as far away as Hamilton to help with the effort," Mr Twyford said.
"We... can conclude this would be a significant setback to the convention centre, which is a hugely important project for Auckland."
He said it was too early to say what the financial implications would be.
"We'll be looking to get advice for what it means for the construction schedule and get back on the front foot."
Internal Affairs Minister Tracey Martin acknowledged the fire during Parliament today, acknowledging the "incredible efforts going on at the moment in Auckland by the fire and emergency services".
Auckland Central MP Nikki Kaye said the fire was "devastating".
"I know that many members of this House will be concerned for those people and, obviously, have extraordinary respect for our firefighters across New Zealand. Our thoughts are with everybody affected by this."