Will Australia take up NZ's refugee offer now?

New Zealand is likely to renew its offer to take some of Australia's detained asylum seekers now Australia's got a new leader, an international law expert says.

Scott Morrison took over as Prime Minister on Friday, after closely winning a runoff against Peter Dutton.

"Our Prime Minister has an offer [to take] 150 asylum seekers from Nauru or Manus Island - it's quite possible he would accept that offer," Waikato University professor Al Gillespie told Newshub.

Previous leaders Julia Gillard and Malcolm Turnbull declined New Zealand's offer, not ruling it out but not taking advantage of it either.

According to the Australian Asylum Seeker Resource Centre, there are currently almost 2000 people being held at sites like Nauru, Christmas Island, Manus Island and Villawood. The number has fallen significantly since 2013, when there were more than 10,000.

On average they spend 428 days in detention.

Jacinda Ardern used her first overseas trip as New Zealand Prime Minister to push Malcolm Turnbull on the refugee issue, and will likely bring it up with Mr Morrison at the first opportunity.

"They're going to be meeting at the Pacific Island Forum in September, and if the offer's remade it could change quite quickly," says Prof Gillespie.

Mr Morrison is a hardliner on immigration and refugees.

"It's likely that the relationship between Australia and America will remain strong and possibly get stronger, as Morrison is probably more aligned to some of the views [US President Donald] Trump has," says Prof Gillespie.

Mr Morrison tweeted on Saturday afternoon he and Mr Trump "had a great discussion" which "affirmed the strength of the relationship between the US and Australia".

Mr Trump is considering visiting Australia in November.

Newshub.