The Prime Minister is talking tough about Australia's deportation policy, ahead of the new PM visiting New Zealand later this week.

John Key said the policy will be a main topic of conversation during Malcolm Turnbull's visit, including the use of detention centres for those awaiting deportation.

Key believes the policy doesn't reflect how close our countries are.

"I think Malcolm is very keen to make his first international call one to New Zealand to reflect that relationship and we have a lot of things to discuss."

He said New Zealand is disproportionately affected because there are so many of our citizens in Australia.

"When politicians on both sides of the Tasman talk about the fact that Australia and New Zealand are family I think they actually mean that, but one of the ways of demonstrating that would be a bit more flexibility about where the threshold is set for this particular policy."