Foreign Minister Julie Bishop insists Australia has been clear and consistent about its boats policy despite being urged to clarify any promises it made to the United Nations' refugee agency.
The UNHCR says it agreed to help administer the deal to send refugees to the United States on the condition that Australia would consider resettling vulnerable refugees on Manus Island and Nauru who have close family in the country.
It said the understanding was reached over months in a number of meetings with senior government officials, but would not identify exactly who.
Related reading
Australia backtracked on settling vulnerable refugees: UNHCR
UNHCR's assistant high commissioner for protection Volker Turk said about 36 people had been identified for resettlement in Australia.
But Ms Bishop insists Australia's position has been clear.
"If people seek to arrive illegally, if they pay criminal smuggling networks, they will not be resettled in Australia," she told reporters in Canberra on Tuesday.
Asked if that means the UN agency was making it up, she said she was not casting aspersions.
The UN's claim has been rejected by Immigration Minister Peter Dutton, with his office reiterating that those transferred to regional processing centres will never settle in Australia.
Fellow frontbencher Michael Sukkar echoed their defence.
"I think what we say privately and what we say publicly is always the same here," he told Sky News.
Labor frontbencher Jim Chalmers said Mr Dutton and Malcolm Turnbull had big questions to answer.
"They need to urgently clarify the arrangement that was made with the Americans and any involvement from the UNHCR," he told the ABC on Monday night.
"They need to clear this up sooner rather than later because there does seem to be a pretty extraordinary difference between the account provided by the agency and the account provided by the Turnbull government."
The one-off deal with the US was announced last November.
More than 1600 refugees have expressed interest in the US resettlement deal, but only about 1200 places are expected to be on offer.
