The United Nations has urged Australia to resettle the refugees who have been languishing on Manus Island and Nauru for the past five years, rather than focusing on the plight of persecuted white South African farmers.

Key points: UNHCR in Canberra says it is yet to receive any queries from white South African farmers seeking protection in Australia

UNHCR in Canberra says it is yet to receive any queries from white South African farmers seeking protection in Australia Spokesperson said those transferred to offshore processing centres in PNG and Nauru should be first priority

Spokesperson said those transferred to offshore processing centres in PNG and Nauru should be first priority Government has told refugees in those centres they will never be resettled in Australia

As pressure mounts within the Coalition to help resettle the farmers, the UNHCR has cast doubt on whether South African farmers can be classified as refugees and granted protection under Australia's humanitarian program.

"The UNHCR Regional Representation in Canberra has not received any queries from South African farmers seeking protection from Australia," said UNHCR spokesperson Catherine Stubberfield.

"Under the 1951 Refugee Convention, a person must be outside their country of origin in order to claim asylum."

In contrast, she said the hundreds of refugees on Manus Island and Nauru have sought protection "directly from Australia" and deserve the Government's attention.

"Those who have been forcibly transferred to Papua New Guinea and Nauru under the 'offshore processing' arrangement should be Australia's first priority after almost five years," she said.

But the Government has told the refugees they will never be resettled in Australia and can either return to their home country, continue living in PNG and Nauru or move to Cambodia.

Government says it has received 'number of applications from South Africans'

Earlier this year, Home Affairs Minister Peter Dutton asked his department to look at ways of resettling white South African farmers arguing they deserved special attention from a "civilised country".

Under Australia's humanitarian program, anyone seeking asylum can apply for a refugee visa or, in a small number of cases, a special humanitarian visa.

The UNHCR plays a crucial role in the process as the agency identifies the vast majority of people in need of protection and refers them to Australia for resettlement.

Since the issue of persecuted white farmers hit the headlines in Australia, the Federal Government said it had received a "number of applications from South Africans", although it is unclear whether they have applied for protection.

The Government has so far ruled out a special visa category for the white South Africans and has been at pains to point out that Australia's immigration program does not discriminate.

But it is still under pressure from a group of conservatives to help the farmers, with some even suggesting a one-off intake similar to Australia's response to the Syrian crisis.