PNG PM flags end of Manus detention

Papua New Guinea's prime minister has signalled he hopes to see the closure of the immigration detention centre on Manus Island, but the timing was up to Australia.

Peter O'Neill told the National Press Club in Canberra on Thursday that hosting the Australian-run immigration detention centre had damaged PNG's reputation.

"Our communities have been accused of many things," he said, noting Manus Islanders were among the loveliest people in the world.

The PNG government did not have the resources to cover the ongoing costs of resettlement of refugees.

"At some stage of course we need to close the centre, these people cannot remain on Manus forever."

Mr O'Neill will have bilateral talks with Prime Minister Malcolm Turnbull on Thursday afternoon.

A delegation of Australian and PNG ministers including immigration ministers had official talks on Thursday morning.

Greens senator Sarah Hanson-Young said the Australian government urgently needed an "exit strategy".

"Clearly Prime Minister O'Neill is sick of his country being used by the Liberal government in this way and it's time to shut the Manus Island camp down," she said in a statement.

PNG's Supreme Court will hear a constitutional challenge to the detention centre in April.

The case involves 600 asylum seekers.

Mr O'Neill said his government would wait for the legal process to take its course.

"You always plan for a worst possible scenario," he told AAP.