"E Ihowā Atua" was written just two years after "God Defend New Zealand" was first performed in 1876.
His response has caused a lot of controversy online, with a petition on change.org calling for the removal of Chong as New Plymouth's district councillor.
The petition has collected 1250 signatures and numbers are growing fast.
Chong, who was elected in 2013, has caused controversy in the past.
In November last year, he revealed why he was happy flying the Confederate flag as well as his decision to defend blackface being used in a Hawera parade.
Speaking to Bryan Vickery on NZME's South Island radio station Hokonui, Chong explained why during an Americana festival he displayed a Confederate flag in his car window.
"I know it's got a history going back and it's about slavery and all that sort of thing, but I see the flag as a part of Americana because when I was a kid this was on the roof if the iconic supercar of its day," Chong said.
The car he is referring is the General Lee that features in the TV series The Dukes of Hazard.
"Sure, it has got a history - but do we actually fully look back, turn around and go the other way? Or do we glance back and look at the history, and make sure we don't make the mistake again?" asked Chong.
"But why hide the history? Let's just have it out there. I've never really had anyone complain because it's Americana. If I flew this any other time, yeah."
Chong then tried to link his argument with Hawera's blackface controversy where a Lions Club's float had six people dressed as black minstrels, surrounded by black and white balloons.
"The same with the black faces - they were doing that to try and bring people together. Other people saw it another way. This is why it's blown all out of proportion," Chong said.
"Some people just need to be not so offended and worry about their own lives, rather than the history of everything else and reading what they read on the internet."
