Immigration Minister Peter Dutton has ruled out sending people illegally detained at Manus Island detention centre to Christmas Island, leaving resettlement on Nauru one of few options left to the government.

Papua New Guinea said it would close the Manus Island centre after its Supreme Court this week found it to be illegal, forcing the government to find an alternative processing centre and settlement options for 850 male asylum seekers and refugees.

Mr Dutton shot down the suggestion by 7.30 host Leigh Sales that the government had a responsibility to process the men on Christmas Island.

"Well, only if you want the boats to restart because that would be a green light for people smugglers ... and you would have drownings at sea," Mr Dutton said during the interview on Thursday night.

"The approach of this government is not going to change. We are not going to allow people to settle in our country who see to come here by boat," he said.

The Immigration Minister said he had been talking with PNG, Nauru and other countries in the region to canvass possible third country settlement options.

The Turnbull government has been in discussion with Nauru, which Mr Dutton said had capacity to accept Manus Island detainees.

When pressed over the responsibility the Australian government had to protect asylum seekers and refugees on Manus Island, Mr Dutton repeatedly abdicated all responsibility to the PNG government, saying only that Australia had a "responsibility within the region".

Earlier on Thursday, Mr Dutton told 2GB radio the PNG Supreme Court's decision "doesn't bind Australia" and did not require the Manus Island centre to close immediately.

"[The 850 men] are the responsibility of the PNG government ... This is an issue that PNG needs to resolve. We will help them resolve this issue," he said.

The Coalition government may share liability for more than $1 billion in compensation claims to the people illegally held in the detention centre.

The Immigration Minister said the government had "restored integrity to our borders" in the face of national security risks.

"We are not going to step back from that position, we are going to make sure, particularly in this day and age with national security is such an important issue, we are going to make sure that our borders remain secure so that we can keep our community in Australia as safe as possible," he said.

On Thursday, Prime Minister Malcolm Turnbull said the people held on Manus Island had the opportunity to settle in PNG or in third countries.

"But they will not come to Australia ... we cannot be misty-eyed about this", he said.