The Defence Force says a quicker tsunami warning system wouldn't necessarily save us.

MORE: Calls for 24/7 quake monitoring service

It follows calls for a better warning system with some saying the confusion following last week's big quake shows it needs sorting out.

Brigadier John Boswell says no matter what technology is in place, people need to heed natural warnings.

He said sometimes it's just a matter of minutes and there's not time for official cautions, like the tsunami that devastated Japan in 2011.

"The people who evacuated, most survived. Those that waited for official warnings, did not."