Thousands of people are preparing to take part in nationwide rallies to mark six years of asylum seekers being processed offshore.
Refugee Shaminda Kanapathi, who has been on Manus Island since 2013, will address supporters via video link on Saturday.
"All of the men who remain detained on Manus are highly depressed and stressed now. We have become very vulnerable and completely powerless," the 28-year-old told AAP on Friday.
"We have no control over what happens to us, even the most intimate decisions are made for us.
"Our lives have stopped. And every minute passes, and we have lost six years already."
There will be 27 rallies held across capital cities and regional towns.
Friday marked six years since the Rudd Labor government reintroduced offshore detention for asylum seekers who arrived by boat.
The prime minister of Papua New Guinea is demanding a deadline for ending the offshore processing of asylum seekers on Manus Island.
James Marape will urge the Morrison government to fix a timeline when he arrives in Australia for an official six-day visit this weekend.
"We would like it to be ended as soon as possible," he told ABC radio.
Mr Marape has already met Home Affairs Minister Peter Dutton to express his concerns.
"I've asked him to expedite the processing of asylum seekers. We need to establish a timeline going forward," he said.
Around 450 asylum seekers remain in PNG and another 350 are being held on Nauru.
"There are genuine refugees and there are also non-genuine refugees. What happens to the rest of them we have in (our) country?" Mr Marape said.
"These are human beings we're dealing with. We can't leave them all hanging in space with no serious consideration into their future."
Greens senator Nick McKim was deported from Manus Island on Friday after being denied entry to an asylum seeker processing centre.
"The veil of secrecy continues to surround Australia's detention centres on Manus Island and Nauru," Senator McKim said.
"As a member of the Australian parliament, it is my duty to examine the conditions in which Australia's detainees are being kept."
Senator McKim was kicked out of PNG despite having an official passport and multiple entry visa.
"In my six visits to Papua New Guinea I have always followed local laws and been respectful to everyone," he said.
"It is the Labor and Liberal parties who wear the shame of this bloody chapter, not the people of Papua New Guinea."
Amnesty International has also used the six-year anniversary to renew its demands to end offshore processing.
"There must be an urgent plan to resolve the situation for all refugees and people seeking asylum on Manus Island and Nauru," Amnesty's Graham Thom told AAP.
"Authorities in Australia should do the only humane thing and immediately bring the refugees and people seeking asylum to safety. The abhorrent practice of offshore detention must end."
Australian Associated Press