US to reveal Manus decision 'in six weeks'

The US will tell dozens of refugees held in PNG's Manus Island detention centre whether they will be offered resettlement in America within six weeks.

The deadline marks the first concrete timetable for the US-Australia refugee swap arrangement that sparked tensions between the allies after President Donald Trump described it as "a dumb deal" for America.

US officials representing Homeland Security this week returned to Manus Island, home to one of Australia's two offshore detention centres in the Pacific, to conduct medical examinations on 70 men.

The men last month completed "extreme vetting" interviews with in-depth questions on associates, family, friends and any interactions with the Islamic State militant group.

After completing the medical tests, refugees were told to expect a decision on their resettlement applications within six weeks, two of the Manus Island detainees told Reuters on Friday.

"They told me I would get a decision within 45 days," said one refugee who declined to be named for fear for jeopardising his application.

It is not clear how many of the 70 men vetted will be accepted for resettlement in the US.

A spokeswoman for Immigration Minister for Immigration Peter Dutton declined to comment.

Former US President Barack Obama agreed to the deal with Australia late last year to offer refuge to up to 1,250 asylum seekers.

In exchange, Australia pledged to take Central American refugees from a centre in Costa Rica.