John Key will make his ninth annual visit to Te Tii marae on Thursday.
The visit is often the site of protests and rancour but Mr Key said political tensions should not dissuade the public from attending.
He told TV3's Firstline politicians "expect the unexpected" at Te Tii but there was more to the day than activists accosting politicians.
"I actually encourage New Zealanders to go to Waitangi on Waitangi Day. It's a family day. Tens of thousands of people go there, the waka are out, it's an absolutely beautiful family fun day and people shouldn't be deterred by what they see as the politicians getting a bit of a hard time at Te Tii Marae the day before."
Mr Key earlier told the Herald he was expecting a "rough" time.
"Down on Te Tii Marae it's normally a pretty robust sort of environment. I've had everything from someone taking a swing at me, right through to being shouted down and being held up for hours before going on there."
On Friday, it will be 175 years since the Treaty was signed.
