High terror threat level in NZ is justified - police

New Zealand's police commissioner says the national terror threat level is being reviewed almost daily.

One month on from the Christchurch terror attack, the threat level remains high and the public should expect an increased police presence for a few more weeks.

"It's absolutely the right thing to do for us to be present in communities, continue to be armed at this present point, to keep people safe, but also give advice to people about what kind of events to hold and how to hold them," Mike Bush told the AM Show.

Five Returned Services Associations (RSAs) in New Zealand have cancelled Anzac Day services, Anzac commemorative events have been reduced in number, and Canterbury University's graduation procession has also been cancelled on advice from police. 

"We're here to make sure people are safe and feel safe, so taking a few precautions is, I think, the appropriate thing to do at this point," Bush said.

The head of the Government Communications Security Bureau, Andrew Hampton, told Newshub last week that as well as the risk of copycats, there is also the risk of retaliation - and not just here in New Zealand. He said it "relates to New Zealand interests offshore as well, which is an important focus for us".

However, Bush assured the public that life will return to normal in a matter of weeks as the current measures are completely precautionary.

"This will wind down, we will go back to normal. The combined threat assessment group look at our threat level almost daily and we know this won't carry on."