Hundreds of refugees being held at a remote Papua New Guinea detention camp will be moved by October despite uncertainty over a resettlement deal with the United States, Australia's immigration minister said Thursday.

Canberra sends asylum-seekers who try to enter the country by boat to camps on Nauru and PNG's Manus Island, with those found to be refugees barred from resettling in Australia.

They are instead relocated to third countries, or resettled elsewhere in PNG.

But the sudden withdrawal from PNG last week of American officials assessing the refugees sparked fears a deal with Washington to take them would not go ahead, particularly after reports earlier this year that US President Donald Trump had described it as "dumb".

The withdrawal of the Department of Homeland Security officials came days after the US passed its annual 50,000-refugee intake cap.

"Our desire was obviously to have them off tomorrow, I want Manus Island to close, we're still going to maintain Nauru," Immigration Minister Peter Dutton told Sky News Australia.

"We have been caught up in the US process, they have a quota each year. It was 110,000 people they were taking in the refugee program under President Obama, but President Trump has reduced that to 50,000.

"Their year finishes in September, so we have been pushed into October in terms of when people will move."

The October deadline was established after a PNG Supreme Court ruling last year declared that holding people in the Manus camp was unconstitutional.

The camps' conditions have been widely criticised by refugee advocates and medical professionals, who say some asylum-seekers suffer from mental health problems due to their prolonged detention.

Australians took part in numerous vigils Wednesday in support of those in detention and to mark four years since the offshore processing regime was set up by the previous Labor government.

More than 800 men are being held on Manus, and 370 men, women and children are detained on Nauru, according to Australian immigration data ending May 31.

The PNG and Nauru offshore detention programme has cost Australia almost Aus$5 billion (US$4 billion) since 2012 according to figures released in parliamentary figures, The Sydney Morning Herald reported Tuesday.

source: AFP