US lawmakers are demanding the details of an agreement to resettle refugees held in Australia's offshore detention centres, asking why Australia "refuses to admit these individuals".
The Guardian reported two senior Republicans have written to the Obama administration demanding it release details of the US-Australia refugee deal and accusing it of withholding information from Congress.
The two men also raised "concern" about their country accepting refugees from countries designated as "state sponsors of terrorism".
Veteran Iowa senator Chuck Grassley and Virginia congressman Bob Goodlatte, chairs of their respective houses' judiciary committees, addressed Tuesday's letter to Secretary of State John Kerry and Secretary of Homeland Security Jeh Johnson.
Secretary Kerry and the Australian Prime Minister Malcolm Turnbull this month revealed the US had agreed to consider resettling an unspecified number of refugees from Australia's Pacific immigration processing camps in Nauru and Papua New Guinea.
Mr Grassley and Mr Goodlatte indicated they had been offered a classified briefing on the deal, but instead called for the agreement to be made available to all members of both houses.
"We firmly believe the American people should be fully aware of the specific details of this agreement and why it was done in secret."
The letter claims Congress learned of the deal through the media, and criticised the administration for not informing legislators during an official refugee consultation in September.
The men said the deal and the manner in which it had been conducted was "concerning" for a number of reasons, including the classified nature of details such as how many refugees the US would accept.
"Your departments negotiated an international agreement regarding refugees without consulting or notifying Congress," they wrote.
"Such information was not disclosed to Congress during the annual refugee consultation that occurred on September 13, 2016, even though your staff confirmed that the agreement had, at the time, been negotiated 'for months'."
They also noted the countries of origin of the likely refugees, which they said were countries of "national security concern", singling out Iran and Sudan as designated state sponsors of terrorism.
"It begs the question why Australia and other countries refuse to admit these individuals, what other countries are doing to help alleviate the situation, what kind of precedent this sets for future refugees interdicted at sea by Australian forces and prevented from entering Australia, and how a similar situation will be prevented in the future."
The Australian government has repeatedly pledged to prohibit any asylum seeker who arrives by boat from ever settling in the country, even if they are refugees.
It said this was to discourage people from risking ocean journeys with people smugglers.