All remaining refugees on Manus Island can relocate to Port Moresby, the Papua New Guinean government has said, offering to continue providing accommodation and health services in the capital city.

According to refugees on Manus Island, notices were issued on Monday informing the 120 or so men left on the island of the offer, which has been cautiously welcomed by Amnesty International.

“Refugees who transfer to Port Moresby will continue to receive services like those currently available to them,” it said.

“Relocation to Port Moresby is not permanent settlement in PNG. [The Immigration and Citizenship Authority] continues to encourage refugees to consider settling in PNG.”

It said anyone who transferred would be provided with residential accomodation in the city, and with a one-off financial relocation support payment as well as a weekly allowance.

“Health services and support will continue, and you will be provided assistance to attend medical appointments.”

In talking points provided to a Manus-based service provider, JDA Wokman, the ICA said refugees were encouraged to settle in PNG, but would be supported to return to their home country if they wished.

Moving to Port Moresby would not affect any applications for US resettlement, it said.

Guardian Australia has previously reported refugee frustration at requirements to fly between Manus Island and Port Moresby for US resettlement interviews.

Graham Thom, refugee coordinator at Amnesty International Australia, said the PNG government was “ultimately doing the right thing”, but expressed concern and called for greater clarity.

“It is vital that there is a long-term plan for these refugees and that their rights are protected. We still have concerns about the men’s safety in the community. Refugees have been targeted in the past and Port Moresby continues to be one of the most dangerous cities in the world,” said Thom.

“Greater clarity about their legal status and how it might affect their ability to settle elsewhere if they choose to transfer is also needed. Some of these men have family in Australia or elsewhere and will wish to join them. While living in Port Moresby offers a lot more freedom than the detention centres on Manus, they should still be allowed to pursue resettlement elsewhere.”

He said the Australian government could not “wash their hands of responsibility” for the men if they moved to Port Moresby.

“Relocating them to Port Moresby should not be seen as a fix-all for the terrible treatment these men have endured over the past six years,” he said.

“[The Australian government] put them on Manus, and they are responsible for ensuring they are suitably resettled, including bringing them to Australia where appropriate.”

Refugees that Guardian Australia spoke with were wary of the offer, saying they weren’t being told what “residential accommodation” meant, and that they were worried after around 50 non-refugees were taken into custody last week.

Around 350 refugees and asylum seekers, who were sent to PNG by the Australian government, remain in the country. Most are now in Port Moresby. Dozens are at the Granville Hotel, transferred there for medical treatment which was unavailable on Manus Island.

The rest are accommodated in other hotels across the city, including the Citi Boutique, where they are subject to unexplained rules and curfews – such as being allowed out for just two hours every second day. Men who have been accepted for US resettlement spend their final weeks in PNG at the Lodge 10 hotel, and are largely free to come and go.

All are guarded by Paladin security officers.

On Manus Island the men are spread across purpose-built accomodation facilities. After a fire – lit by a man in an act of self-harm – damaged rooms at Hillside Haus where men who have been determined not to be refugees are housed, residents were offered to temporarily relocate to Port Moresby.

However last week the ICA detained more than 50 of them, and moved them to an Australia-funded immigration detention centre annexed to the Bomana prison. Refugees and asylum seekers accused the government of tricking the men with the initial offer of relocation.

Behrouz Boochani, a Kurdish Iranian journalist and refugee on Manus Island, said about half the men had never had their asylum claims assessed and were deemed non-refugees because they had refused to take part in the process in the early years of detention. They now want to be assessed.