One of them is Zabihullah Hussaini, a 29-year-old Hazara man who was transferred to the Manus Island detention centre in 2013 and after six years in detention was released in Port Moresby.
"I was 21 when I came to Australia, now I am 29," he told AAP.
"News (of the PNG closure) surprised us all. Every Afghan here was concerned.
"To hear ... that Australia can't support us anymore was like sprinkling salt on our wounds. Some are at breaking point here. One Afghan man says, he wants to end life because there is nothing to hope for."
Afghan citizens are being prioritised for offshore processing, an Australian Border Force spokesperson told AAP in a statement on Saturday.
"Applicants must meet the visa criteria and satisfy public interest criteria for character, security and health," the spokesperson added.
"All humanitarian visa applications are assessed on an individual basis. Processing times can vary according to the particular circumstances of the applicant, their location (be it inside or outside their home country), and their ability to travel, provide documents or access Australian government officials."
While waiting for an Australian determination, Mr Hussaini made an application for asylum in the US, but that was rejected in 2018. He has since applied to enter Canada.
He does not feel safe and now "feels abandoned" in PNG.
The Taliban has driven Mr Hussaini's family out of their traditional home in Afghanistan's Ghazni province, where his cousin was also killed.
"I am very worried where to find sanctuary for them, they are not safe. The Taliban kill us because we are Hazaras. I can do nothing to help. I am trapped here. I feel I am a failure."
Recapturing control of Afghanistan in August after more than two decades of conflict, the Taliban has been accused of "the brutal massacre of the Hazara men" in southern Ghazni province by a recent Amnesty International report.
The Border Force spokesperson said "no Afghan visa holder currently in Australia will be asked to return to Afghanistan while it would be unsafe".
While Australia will end its offshore program in PNG, processing will continue in Nauru.
"Anyone who attempts to enter Australia illegally by boat will be returned or sent to Nauru," Home Affairs Minister Karen Andrews has said.
The Refugee Council has called on New Zealand, US and Canadian governments to assist resettling the remaining refugees.
"It is laughable for the Australian government to pretend that it no longer has any responsibility for people it transferred to PNG," council spokesman Paul Power said.