Kieran Read says New Zealand have no concerns that they could be knocked off the top of the rankings this weekend ahead of a blockbuster showdown with Australia.

The All Blacks head into the Bledisloe Cup clash in Perth on Saturday knowing a defeat at Optus Stadium will open the door for Wales to become the top-ranked side in the world.

A win for the Six Nations champions over England on Sunday and a loss for Steve Hansen's side would take Warren Gatland's men to number one.

Captain Read stated that the world champions have not given any thought to the possibility they could be knocked off the top as they prepare for another battle with their fierce trans-Tasman rivals.

The back-row said: "It's not even part of our equation really, to be honest.

"We turn up here to win the game. We'll try and do that again tomorrow. We know it won’t be easy and it never is over here. We’ll put in our best performance."

New Zealand have won 10 of their last 11 Tests against the Wallabies but Read is expecting a big challenge.

"They’ve definitely had the fire in their bellies the last few years." he added.

"We know they will certainly have that again tomorrow night, so we can't just rest on what we've done over those years. It's important we reset and make sure we play as well as we can.

"These games you can't rely on your skills. It's about your mental fortitude and how you turn up and how you want to be physical. It's going to be important for us how we do that tomorrow."