GeoNet's call for extra funding so it can be staffed around the clock was an 'unreasonable criticism', according to acting Civil Defence Minister Gerry Brownlee.
Mr Brownlee said he was blindsided by comments made by Geonet's director Ken Gledhill following last Monday's 7.8 magnitude earthquake.
Dr Gledhill said Geonet could not give tsunami warnings as quickly and accurately as he would have liked, because it was not staffed overnight or on weekends, and relied on staff who were on call.
But Mr Brownlee said Dr Gledhill's call for more funding was an unreasonable criticism made at a time when people were suffering.
"It's quite clear that GNS may have included some commentary about a 24/7 in various reports, but they have never ever provided anything directly to government, or close to it, asking for that particular initiative."
GeoNet is a collaboration between GNS Science and the Earthquake Commission.
Mr Brownlee said he felt blindsided by the suggestion that there wouldn't have been the "kerfuffle" over the tsunami warnings if Geonet had a 24/7 watch.
"We're not closed to looking at this possibility looking forward, but you can't just magic something up overnight and I think the irritation with Mr Gledhill deciding effectively to raise something that I think was an unreasonable criticism at a time when people were suffering," he said.
Dr Gledhill declined to respond to Mr Brownlee's comments.
The past president of the New Zealand Association of Scientists Nicola Gaston said Dr Gledhill spoke out only because he wanted to keep the public safe.
"Any New Zealander who has a deep sense of concern about the way we run these systems should feel able to speak publicly about their concerns.
"I don't think that's any less true if you have the expertise based on running essential parts of these emergency response systems."
Dr Gaston said the current government had a habit of vilifying scientists, who in turn were becoming very cautious about speaking publicly.
The association called on the government to avoid behaving in a manner that could lead to scientists being discouraged from speaking out on matters involving public safety.