Turnbull refugee generosity queried

Labor and aid groups say Malcolm Turnbull's announcement Australia's refugee intake will be maintained at 18,750 falls short of what is needed.

The prime minister told US President Barack Obama and other leaders at an invitation-only high-level summit on refugees and migration in New York his government would lift the intake from 14,000 to 18,750 from mid-2018, and keep it at that level.

Australia will also take part in a US-led program to resettle Central American refugees now in a resettlement centre in Costa Rica.

As well, an extra $130 million over three years will go to support peace building and assistance to refugees, forcibly displaced communities and host countries - building on the already-announced $220 million commitment to Syria and neighbouring countries.

Labor leader Bill Shorten dismissed the pledge as a "hoax", accusing Mr Turnbull of reheating a policy announced by Tony Abbott in 2015.

"They haven't dealt with the elephant in the room ... we have nearly 2000 people trapped in almost indefinite detention on Manus and Nauru," Mr Shorten said in Adelaide on Wednesday.

Mr Turnbull needed to explain whether Australia was in talks with Canada, New Zealand, the US or Asian countries on where to resettle those processed on Nauru and Manus Island, he said.

Oxfam welcomed the overall strategy but chief executive Helen Szoke is disappointed there is little actual increase to Australia’s humanitarian intake.

"It is a step in the right direction but not a new announcement,” Dr Szoke said.

With an estimated 65 million people displaced worldwide, Oxfam says the intake should be lifted to at least 30,000 by 2018/19 and 42,000 by 2020/21.

Dr Szoke said the Australian government must resettle the 12,000 Syrian and Iraqi refugees they agreed to take in a year ago by the first quarter of 2017.

Save the Children said Australia was more than able to take in extra refugees.

"Swiftly increasing Australia’s humanitarian intake to 30,000 places by 2018/19 would have been a much better response to the current scale of the crisis and a truer reflection of Australia’s social and economic capacity to resettle refugees," chief executive Paul Ronalds said.

In his speech, Mr Turnbull urged world leaders to do more to address the underlying causes of displacement, including providing more assistance in home countries.

Australia's stopping of asylum seeker boats paved the way for one of the world's most generous humanitarian systems, he said.

"Australians support these actions because they have confidence that our migration system is well managed," he said.

Treasurer Scott Morrison said Labor had a plan to take more refugees but "they just don't have a plan to fund it".

He said the government's program was fully funded.

The former immigration minister said it was routine to set an intake level each year and provide guidelines to the department on where the refugees come from.

Under his watch, at one point there was a focus on taking in Burmese refugees from camps in Malaysia and Thailand, so the decision to focus on Costa Rica was not unusual.

"We are not anticipating a large intake out of that area," he told Sky News on Wednesday.