Australian police officers will be deployed to train and support their Papua New Guinea counterparts as part of a new security deal inked between the two nations.
Prime Minister Anthony Albanese hosted PNG leader James Marape in Canberra on Thursday where the deal was signed.
The legally binding agreement will help benefit nations and add to regional security, Mr Marape told a joint press conference after the meeting.
"You've always given support to us - what happens up north of your borders has ... effects, benefits, consequences for our region," he said.
Policing and domestic security had been identified as priority areas in the agreement, Mr Albanese said.
"It will make it easier for Australia to help PNG address internal security needs and for Australia and Papua New Guinea to support each other's security and the region's stability," he said.
Australia had hoped to have the pact signed in the first half of the year but it was delayed after a backlash in PNG, when a similar agreement with the United States caused a domestic uproar about a loss of sovereignty.
The Pacific island nation and Australia's closest northern neighbour has been struggling with tribal violence in its highland region.
Mr Marape at one stage instructed police and military to use lethal force to curb the violence if necessary.
Australia has been looking to bolster its security arrangements in the Pacific after China signed a policing pact with the Solomon Islands.
There are concerns in Canberra about China securing a foothold in the region.
But PNG's signing of agreements with Australia and the US should not be seen as picking sides, as it didn't come at the expense of any other nation, Mr Marape said.
"Our major foreign policy of friends to all and enemies to none remains," he said.
Mr Marape will address the Australian parliament on February 8.
Dominic Giannini - AAP