Malcolm Turnbull has weighed into the row over US President Donald Trump's decision to invite the Philippines President Rodrigo Duterte to the White House.
The Philippines leader's so-called "war on drugs" has resulted in the deaths of an estimated 8000 people.
Authorities have denied that extrajudicial killings have taken place, but human rights groups believe many deaths police attributed to vigilantes were carried out by assassins colluding with police.
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The prime minister had bilateral talks with Mr Trump in New York on Friday and is en route back to Australia ahead of Tuesday's federal budget.
"The Philippines is a vitally important nation in our region," Mr Turnbull told Fox News before his departure.
"Naturally the United States will be reaching out to, and dealing with... all of the nations in the region."
Asked about what message the invitation sends to Mr Duterte over human rights, Mr Turnbull said it was "a matter for the president to raise with his counterpart at the appropriate time".
"It's in the national interest of my country Australia and indeed in the national interest of the United States to have strong engagement with all nations in the Asia-Pacific and that includes the Phillippines," he said.
The White House has defended the invitation saying Mr Duterte's cooperation is needed to counter North Korea.
It's unclear whether Mr Duterte will actually accept the invitation, with the president saying he's tied up and can not make a definite promise.
Mr Duterte called former US President Barack Obama "son of a whore" in September following after he criticised the controversial war on drugs.
Since coming to power last June, Mr Duterte has shifted Philippine foreign policy distancing the country from the US and aligning it more with China.
During a doortop appearance with jounalists before heading back to Australia, Mr Turnbull was asked about Australia's immigration policy.
"Well can I just say on migration, Australia’s policies are well understood. Of course, we talk about our immigration policies which are built on a foundation of saying that it is the sovereign right of the Australian Government – elected by the Australian people – to decide who comes to Australia and how long they stay and the terms and conditions on which they stay," he said.
"So that is our sovereign right.
We are the most successful multicultural society in the world. That is my claim as Australia’s Prime Minister. The foundation of that is a migration system in which the Australian people have confidence that their Government is completely in control of. That is what we’ve established and that is what we maintain and that is what’s understood by others."
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